It is better to lower our consumption and swap white sugar for more dietetically correct options. Whole sugar, honey, syrups... Discover all the alternatives.

Classic sugar, crystallized or in pieces, is not of much interest. Poor in nutrients, it provides about 20 kcal per piece or teaspoon and panics blood sugar. Like all sugars added or hidden in industrial products, it promotes hyperinsulinism and the storage of abdominal fat. As a result, it is one of the main culprits of metabolic syndrome diseases (diabetes, obesity, etc.). It would feed the cancer cells! Not to mention its role in the phenomenon of glycation, a kind of 'caramelization' of our cells that accelerates ageing. In short, red card!

Whole sugar

Ever heard of rapadura®? It is not a distant destination, but a complete cane sugar, that is to say unrefined, which can be found in organic shops. We gain some vitamins and minerals, but also fiber that reduces its impact on blood sugar levels – and therefore on the scale. With its small taste between caramel and licorice, it slips easily into dairy products, fruit salads or cakes. A good plan. Coconut sugar, also unrefined, has its charm in recipes based on exotic fruits (banana cake, mango tatin, etc.). It combines a subtle taste with a low glycemic index.

Honey

Difficult to make more natural than this product of the hive! Its bonus points: honey contains a little fewer calories and especially more nutrients than sucrose. Adding a small spoon is a good alternative to bring sweetness to yoghurts, cottage cheeses, herbal teas or teas if you are reluctant to swallow them 'plain'.

Fructose, in very small doses

It is naturally present in fruits, but can also be bought in sachets to decorate our hot drinks or prepare our jams. As its sweetening power is 1.5 times higher than that of conventional sugar, we put less. However, it is better not to use it systematically, because several studies show that excessive consumption (more than 50 g / day) increases triglycerides and cardiovascular risk. We alternate as much as possible with the other jokers.

Syrups

Agave syrup, extracted from the sap of a cactus, is liquid-like honey and contains more than 70% fructose, which causes blood sugar to rise very little. It also has 100 fewer calories per 100 g than powdered sugar. Two good points, then. To try in yoghurt but also in the pastry. Another option: a few drops of maple syrup, made in Canada, in pancakes, of course, but also to give an original touch to a compote, for example. It is natural (provided you choose it pure) and a little less rich than honey.

Watered-down versions are avoided

By bringing a sweet note but zero calories, sweeteners seem essential when you watch your line. However, it is better not to abuse it. Because by maintaining our addiction to sweets, they do not necessarily help to reduce our overall consumption and it is not easy to find our way among all these 'fake sugars'. Aspartame is now controversial (some studies point to the dangers of ingestion at high doses) and is already swallowed in light products. Unlike him, stevia (made from a plant extract but not really 'natural' for all that) or sucralose support cooking well. They are found in all forms: powder to flavor our desserts, lozenges for the sweet gesture and even in pieces to boost coffee. Problem: there is a lack of perspective on the safety of stevia, which has recently arrived on the shelves, and sucralose could in the long term increase our response to insulin. Birch xylitol, extracted from the bark of the tree and sold in powder, is praised for its anti-caries effect, but beware of excesses (it can cause bloating and stomach aches). The best is to alternate and especially not to make it a systematic reflex. You can also try the coffee without sugar, to see...

3 tips to reduce the dose

Between the sugar that is sprinkled right to left, that of sweets that console and that present in industrial products (sodas, fruit juices, dairy products, bread and pastries but also prepared dishes, sauces, dressings, crumb bread, etc.), it is the accumulation! Three anti-overdose tips from the book Detox Sugar Program in 7 Days, by Dr Pierre Nys, endocrinologist nutritionist (Éditions Leduc. S).

• During a day, we add zero sugar (for example in tea or coffee) and we completely eliminate sweet products that are not natural (cakes, sweets, spreads, jams, chocolate ...): it allows you to realize that you consume a lot. Then we take up the challenge over a whole week to rest our saturated taste buds.
• We buy a maximum of simple and "natural" foods to reduce hidden sugars: fruits and vegetables, dried fruits, fish, meat, ham by the cut rather than under vacuum, pasta and brown rice, potatoes, lentils and other legumes, wholemeal bread instead of bread, yoghurts and plain cottage cheeses, herbs and spices,  etc.
• We give ourselves the equivalent of a little honey or two squares of dark chocolate a day if the desire for sweetness titillates us. Everything else must remain an exceptional little pleasure, once a week, no more.

 Losing weight has long raised many questions, questions and debates among women. Some choose to follow a draconian diet while others prefer to lose weight through physical activity. But what is the best technique to lose weight and avoid the yoyo effect?

Women's Sport Program

Before getting to the heart of the matter, we must forget about the miraculous slimming diets that claim that it is possible to lose 5 kg in 5 days. In addition to being dangerous to health, these techniques can only refine the body for a short time. Research has shown that the best way to lose weight is to combine proper physical exercise with a balanced diet. For a beginner, it is advisable to do a morning jog, cardio training or practices an individual sport (swimming, tennis, skiing, cycling, etc.) or collective sport (basketball, volleyball, handball, etc.) once or twice a week. The duration of the session varies from 30 to 40 minutes.

Sports program to lose weight and women's weight loss

As pointed out above, you have to be careful about what you eat. To lose weight effectively, avoid foods high in sugar and fat, such as hamburgers, fries, steaks, sugary soft drinks as well as anything else on offer in fast foods and fast food establishments. On the other hand, it is better to follow a healthy menu based on fruits and vegetables while favoring the consumption of white meats such as turkey hams or white fish.

Homemade sports exercises to lose weight and lose weight

There is a multitude of exercises to practice to promote weight loss regardless of your metabolism. Here are 5 of them:

Sheathing

This exercise is different from the others in that it is performed with minimal movement. The person who engages in sheathing lies facing the ground, relying uniquely on his forearms and tiptoes. The pelvis is raised while the body is straight and well stretched. The gaze, meanwhile, focuses on a point in front. A sheathing sequence lasts 30 seconds. For this exercise to be effective, it is important to do 5 to 10 repetitions. For information, sheathing allows having firm abdominals, to get rid of the saddlebags and to eliminate the love handles (the fatty deposits located on the hips and on the lower abdomen).

The burpees

Burpees is a popular aerobic exercise. It involves many muscles such as the pectorals, shoulders, triceps and quadriceps. The starting position of this exercise is standing. It is then a question of putting oneself in the pump position after flexing the legs and throwing them, well stretched, back. By pressing on both hands, it is possible to touch the ground with the chest. Then return to the starting position by executing the movement in the opposite direction. Once standing, stretch your arms above the head, then make a jump in extension. The whole movement should be carried out 5 times.

The jumping jack

This exercise is very simple. Standing, it is enough to make jumps on the spot by spreading, then closing the arms and legs. Repeating this movement 5 to 6 times gets rid of cellulite in the belly, hips and thighs. As a result, the body becomes thinner and the extra pounds fly away.

The squat

The squat is the favorite exercise of female celebrities. It is ideal for obtaining steel buttocks and thighs. In a standing position, legs apart, and arms outstretched, one should flex the legs until they form a 90° angle with the ground. Then it is necessary to exhale slowly and return to the initial position. To lose weight and have muscular buttocks, it is recommended to do 5 sets of 5 repetitions.

Walking slots

Here are the instructions to follow to carry out this exercise. In the first place, you have to stand with your back straight. Then spread the feet until they are parallel to the width of the shoulders. Take a big step forward with one of the legs. The detachment of the heel from the back leg must be synchronized with the step taken. It is also necessary that both knees form a right angle. The repetitions to be performed are 10 per leg.

Weight Loss, Bodybuilding Program

Bodybuilding is intimately linked to weight loss, as exercises intended to increase muscle mass are accompanied by a strict diet program and a cardio training program. To refine the figure and have protruding muscles, it is necessary to follow precise exercises and be assisted by a bodybuilding coach. However, the mass gain is different in women. Genetically and hormonally, they hardly gain muscle compared to men. This is explained by the fact that the testosterone level of women is lower than that of men. Their muscle and bone structures are also different from their male counterparts. Nevertheless, with rigorous training, it is quite possible for women to gain muscle. Below are some rules to respect for good progress and to avoid overtraining:

• Warm-up for about 15 minutes before weight training (to raise the temperature, prepare the body for the exertion and to reduce the risk of injury);
• Alternate the work of the upper body and lower body;
• Prepare specific exercises specific to each muscle group (arms: curls, developed at the helm, extensions...);
• Respect the rest times between each set (about 30 seconds);
• Do not work more than 3 muscle groups per session.

Note that 2 bodybuilding sessions per week are enough for a beginner. Practising bodybuilding exercises overnight and at high intensity can have serious impacts on your body: to be banned.

Women's sports program to refine

To have a slim and athletic body here is a simple and easy sports program:

Running

To remove fat in the thighs and calves, it is recommended to run for about 10 minutes outdoors or on a treadmill if the weather conditions do not allow you to go out. To start, you have to hold a moderate speed, then gradually increase the pace. The best is to look 50 m forward and try to throw the legs forward and not up. Shoulders and hands should be relaxed and relaxed. Research has shown that an hour of running loses 850 kilocalories.

Jumping rope

Jumping rope provides many benefits to the body. It improves balance, endurance and optimizes respiratory capacity. However, this sports activity is not recommended for people suffering from low back pain and arthritis. Before starting, you have to choose the rope well. Its length should be proportional to the size of the individual. In addition, you should not indulge in this sport with bare feet.

Swimming

Swimming is a complete sport. It helps to tone and firm the arms, abdominals and legs. The reason is quite simple: the muscles are more stressed in the water because of the pressure. Moreover, swimming can be practiced by everyone: children, teenagers, adults, the elderly and pregnant women.

Women's Fitness Program to Lose Weight

Exercises to tone muscles, to soften and energize tendons and joints and to improve physical fitness are:

• Aquagym;
• Cycling;
• Zumba;
• Muscle-strengthening exercises (thighs-abs-gluts).

Weight loss training

 The glucose that circulates in the blood comes mainly from the carbohydrates (sugars) that you consume. In the presence of diabetes, your body misuses the energy that circulates in the form of glucose in the blood, which can cause your blood sugar (blood sugar) to rise above normal values.

A person with diabetes does not have to eliminate all carbohydrates from his diet: carbohydrates are the main source of energy for the body and the only fuel for the brain. Instead, she should closely monitor the amount ingested and spread it over at least three meals to control her blood sugar.

Carbohydrate sources

Carbohydrates form the set of sugars found in food. They include sugars, starch and dietary fiber.

Sugar can be naturally present in foods or added:

• Natural sugars: they are found naturally in milk and its substitutes, starchy foods, legumes, fruits and vegetables (in smaller quantities) as well as their juices, etc.
• Added sugars: They are added to cookies, sugary drinks, sweets, cakes, and other commercial products.

Whether carbohydrates are naturally sourced or added, they turn into glucose to provide energy to the body's cells. So they all have an impact on blood sugar.

Simple or complex carbohydrates?

Carbohydrates can be classified into two broad categories:

1. Simple carbohydrates: the most common are glucose (dextrose), fructose, lactose and sucrose. They are absorbed quickly by the body. They can be found in:

• fruits and their juices
• milk and yoghurt
• sweet foods (pastries, chocolate, jams and syrups)
• refined sugar (white sugar (sucrose), honey, molasses, maple syrup, etc.)

2. Complex carbohydrates: These carbohydrates are made up of several units of glucose combined into a long chain called starch. They are absorbed more slowly by the body and do not give a sweet taste to food. They are found in foods that contain starch, often called starchy foods:

• bread
• crackers
• cereals
• rice and pasta
• legumes
• potatoes

Dietary fiber is also part of the complex carbohydrates, however, unlike all other carbohydrates, it does not have an impact on blood sugar, because it is neither digested nor absorbed by the body.

Nutritional advice

Carbohydrates have a direct influence on blood sugar levels, which is why it is important to control the amount consumed and to distribute their consumption throughout the day, over at least 3 meals.

You should give preference to carbohydrates from foods that have interesting nutritional value (rich in vitamins, minerals and fiber).

Carbohydrate-rich foods that have good nutritional value are mainly:

• cereal products (preferably whole grain – rice, pasta, bread, cereals, etc.)
• vegetables and fruits
• milk and certain dairy products
• legumes (chickpeas, lentils, etc.)

A variety of foods from these categories should therefore be regularly on your menu.

Refined sugars can be consumed occasionally and moderately, as part of a balanced meal containing other carbohydrates, protein and fat.

Taken as part of a meal, sugar will have less impact on blood sugar.

For the person with type 2 diabetes or those with an eating plan with predetermined amounts of carbohydrates for each meal, refined sugars, when consumed, should replace other carbohydrate foods usually ingested, not be added to them. The total amount of carbohydrates should remain roughly the same day by day.

If you're buying processed products, take the time to read the Nutrition Facts table and ingredient, list for the presence of carbohydrates.

Be aware that food without added sugar is not necessarily free of carbohydrates: carbohydrates can be found naturally in food (e.g., fruit juice without added sugar contains the natural sugar of the fruit).

Carbohydrate requirements

The amount of carbohydrates people need each day depends on different factors:

• age
• gender
• size
• weight
• the level of physical activity

• 45 to 75 g of carbohydrates per meal
• 15 to 30 g of carbohydrates per snack, if necessary

Note that adolescents, athletes and young adults with type 1 diabetes may have higher needs.

Your nutritionist/dietitian will help you determine how many carbohydrates you need.

Low-carb diets

Health Canada recommends consuming at least 45% of total energy (calories) as carbohydrates (sugars).

So what about low-carb diets that contribute between 4 and 45% of total energy? Although they would allow a decrease in triglycerides, current studies do not show that such diets could have a definite effect on the control of blood sugar (blood sugar), the improvement of blood pressure or blood lipids or the management of body weight in the medium or long term in people with type 2 diabetes.

Given the lack of long-term studies, it is impossible at this time to know the future impacts of carbohydrate-restricted diets, and thereby ensure that they are safe. However, we know that they can cause nutritional deficits (vitamins, minerals, antioxidants, fiber, etc.) and lead to the overuse of the kidneys.

 Breakfast, often referred to as the king's meal is a key moment of the day. Very important to break the fasting of the night and start the day on the right foot, it is nevertheless often shipped.

Lack of time and appetite are two factors that push to turn to easy solutions.

In this article, discover 5 quick breakfast recipes to lose weight.

How to compose a balanced breakfast to lose weight?

Breakfast is a very important meal for the body. Many studies show the interest in a balanced breakfast to prevent overweight and associated health problems.

Not all breakfasts are created equal. Especially since supermarkets are full of breakfast products intended to make our lives easier, but which are not always balanced: pastries, biscuits, cereals, industrial fruit juices, etc.

If you want to lose weight, you must respect certain rules concerning the composition of a well-balanced breakfast, here is what you take in the morning:

• A fruit or equivalent: 100% pure juice, whole fruit, compote;
• a source of lean protein: dairy, cheese, eggs, lean meat;
• cereals rich in fiber: oats, wholemeal bread, cereal, bread, rusks, unsweetened cereals;
• quality lipids: margarine, vegetable oil, oilseeds, seeds;
• An unsweetened drink to rehydrate the body: coffee, tea, herbal tea, lemon water, infused water, 100% pure juice.

We offer 5 easy and quick recipes to prepare for a perfect slimming breakfast.

Porridge with oat bran

Recipe for 1 person:

• 2 tbsp oat bran;
• 150 ml of almond or cow's milk;
• 1 tsp honey;
• 2 drops of liquid vanilla extract;
• 100 g of seasonal fruits: red fruits, pear, apple, mango;
• 5 crushed almonds.

Preparation of porridge

1. To make the porridge with oat bran, put the milk and liquid vanilla extract in a saucepan. Heat gently then add the honey and stir until dissolved;
2. Then, integrate the oatmeal into the warm milk and then cook over medium heat for 5 minutes. Once the desired consistency is obtained, place in a ramekin and let cool;
3. ideally, this porridge with oat bran and to be made the day before and should spend a night in the cool;
4. Just before serving, cut the fruit coarsely. Then, place them on top with the crushed almonds of the porridge before enjoying it fresh.

Why choose oat bran porridge for a diet breakfast?

Smoothie bowl with red fruits, a concentrate of nutrients

Recipe for 1 person:

• 1/2 frozen banana;
• 150 g of red fruits;
• 100 ml of vegetable milk;
• 1 tbsp Chia seeds;
• 1 tbsp grated coconut;
• Some red fruits for decoration.

Preparation of the smoothie bowl

1. To make the red fruit smoothie bowl, start by thoroughly washing your red fruits with clear water;
2. Then, in the bowl of a blender, place the frozen half banana, red fruits and vegetable milk. Mix until a smooth and homogeneous mixture is obtained;
3. Once the smoothie is mixed, place it in a bowl and then sprinkle it with fresh red fruit, grated coconut and Chia seeds. 

Why is the smoothie bowl ideal for a slimming breakfast?

The smoothie bowl can be declined with all the fruits you have at your disposal. Concentrated in antioxidants, fiber and vitamins, it is a great way to fill up on nutrients as soon as you wake up. In addition, it is quick to prepare and very satiating.

Homemade cereal bars with oat bran

Recipe for 2 cereal bars:

• 50 g of oatmeal;
• 1/4 ripe banana;
• 15 g hazelnuts;
• 10 raisins;
• 1/2 tsp bitter cocoa;
• 1 tsp honey or agave syrup.

Preparation of homemade cereal bars

1. To make homemade cereal bars with oat bran, preheat your oven to 180°C. Rehydrate the raisins for 5 minutes in hot water;
2. in the bowl of a blender, mix the banana with the bitter cocoa and honey;
3. Then, in a bowl, mix the oatmeal, crushed hazelnuts and rehydrated raisins. Incorporate the mixed banana mixture into this preparation. Then, mix well so that the banana completely permeates the dry ingredients;
4. Then, on an oven-safe sheet covered with parchment paper, spread the mixture to a thickness of 1.5 cm. Bake for 15 minutes. At the end of cooking, the preparation must be well browned;
5. Finally, cut out two cereal bars. You can multiply the quantities, these cereal bars keep very well in an airtight box.

Why are homemade cereal bars a good breakfast for weight loss?

These homemade cereal bars are a great healthy alternative to traditional industrial cereal bars. Rich in fiber and very low in sugar, they are ideal for a slimming breakfast on the go. Indeed, it is bananas, raisins and honey that serve here as 100% natural binders and sweeteners.

Complete avocado and fresh cheese toast

Recipe for 1 person:

• 50 g of wholemeal bread;
• 1/2 lawyer;
• 1 fresh square;
• The juice of half a lemon;
• Some pumpkin seeds;
• Salt, pepper.

Preparation of the complete toast

1. To make the complete avocado and cheese toast, start by toasting your slices of wholemeal bread for a few minutes in the oven or toaster;
2. Meanwhile, in a bowl, roughly crush the avocado with the fresh square and lemon juice. Salt and pepper at your convenience;
3. Finally, on the slices of toast, place the avocado cheese mixture. Finish with a drizzle of lemon juice and a few squash seeds for more texture.

Why is the full avocado toast an ideal breakfast to lose weight?

Very quick to make, this avocado toast recipe contains a multitude of good nutrients: quality unsaturated fats, dietary fiber, calcium and protein. Lemon juice is also excellent for stimulating the digestive system in the morning.

Have you made hearty meals? Abused with sugars, alcohol and fats? Is your liver engorged, tired? The good news, some foods can detoxify it naturally after the excesses and improve digestion. Which? Listings and advice with Professor Patrick Marcellin, herpetologist.

Diet has a strong impact on liver health. "What is bad for the liver seems obvious: we must limit alcohol, foods that are too rich in sugars, fats, and avoid the consumption of industrial or processed products, often too rich in additives. An unbalanced diet tends to tire the liver, which can no longer do its job properly and ensure the biochemical and metabolic functions essential to the proper functioning of the body," explains Professor Patrick Marcellin, a hepatologist at Beaujon Hospital and founder and organizer of the Paris Hepatology Conference (International Annual Congress on Liver Diseases). On the other hand, foods rich in antioxidants, minerals (magnesium, calcium, phosphorus, iron) and vitamins (A, B and C) are beneficial for the liver. They help cleanse it of toxins and protect it from liver disease. Overview of the 7 best 'detox' foods.

Dark chocolate

"Contrary to what one might think, chocolate, provided it is black and with a cocoa content greater than 70% is good for the liver. The magnesium it contains has a protective effect on this organ. In addition, it is very rich in antioxidants, which helps to delay the aging of liver cells, rid them of certain toxins and limit inflammation. These substances also have antidepressant and energizing properties," says Professor Marcellin. It goes without saying, but we avoid milk or white chocolate, very low in cocoa and too rich in fats and sugars.

Nuts

Oilseeds (nuts, Brazil nuts, pecans, macadamia, hazelnuts, almonds ...) are extremely rich in phosphorus, "a mineral salt very beneficial for the liver", says the herpetologist.  Phosphorus makes it possible to metabolize lipids, thus digesting and degrading fats and preventing them from accumulating in the liver. Without phosphorus, our liver would be overloaded with fat and we would be more at risk of having a liver disease (steatosis for example). 

Dairy: goat cheese

'Before, milk was a noble food. Today, it has a less good reputation because it is considered too fat and difficult to digest. Consequence: people are enormously deficient in calcium, a nutrient that is essential for the formation and strength of bones and teeth, blood clotting, nerve conduction, the release of hormones, lists our interlocutor. Dairy products, whether milk, cheese or yoghurt are not bad for your health when consumed in moderation and are even beneficial for the liver. We still prefer dairy products low in lipids (cancoillotte or fresh goat...)'.

Green tea

Tea, and especially green tea, is very rich in antioxidants. These molecules activate and detoxify the liver, and thus reduce the risk of developing the liver disease (fibrosis, steatosis, hepatitis...). In addition, its polyphenol content, known for its antioxidant properties, helps reduce the level of lipids in the blood and improves cardiovascular health. It is also a good anti-cancer that can particularly decrease the risk of liver cancer. "We find that in countries where we consume a lot of tea, the number of liver diseases is lower," says the herpetologist. A 2017 Dutch study published in the Journal of Hepatology showed that frequent consumption of green tea (greater than 3 cups per day) reduced the risk of liver stiffness (the stiffer the liver, the greater the risk of fibrosis and therefore the greater the risk of statues or even cirrhosis).

• Warning: 'Some herbal teas or decoctions, with artichoke, for example, are sold in the physiotherapy departments as 'hepato-protective'. They stimulate liver cells and help treat liver dysfunctions (liver failure, etc.). It cannot be said that these products are bad for the liver, however, their effectiveness has never been demonstrated by scientific studies," the specialist said. 

Offal

The liver needs iron: iron is stored mainly in the liver, thanks to ferritin, a protein that transports iron to haemoglobin when needed. "In case of iron deficiency, the immune system is weakened and the liver cells may malfunction slightly. In addition, the liver is able to take the necessary iron without there being a risk of overload (except in the case of a genetic, disease called hemochromatosis). It is, therefore, necessary to take care to consume enough meat, especially red meat (beef) or offal, which are rich in iron, explains the herpetologist.

Foods rich in phosphorus:

• Brazil nuts: 658 mg/100 g
• Pine nut: 527 mg/100 g
• Almond: 481 mg/100 g
• Cashew nuts: 452 mg/100 g

• Warning: an excess of red meat can be pro-inflammatory. The WHO and the National Cancer Institute advises individuals to limit their consumption of red meat (no more than 500 g per week), to favor the consumption of poultry and to alternate with fish, eggs, shellfish and pulses, also rich in iron and protein. 

• Do not hesitate to make an iron, cure twice a year (in spring and autumn), advises Professor Marcellin

Present in fruits and vegetables, fructose has long been considered a 'healthy' sugar. But its use in many processed foods leads to excessive consumption in connection with many pathologies (obesity, fatty liver steatosis, diabetes, cardiovascular diseases ...).

 Fructose is a substance that is an important part of our current diet, especially that from the food industry (sweet drinks, pastries, etc.). This article presents a state of knowledge relating to the effects of fructose on human metabolism. After showing how fructose has a different metabolism from glucose and specifying the interest of its use in the medical field (diabetes) or sports, he explains its long-term effects and its involvement in metabolic diseases.

The consumption of fructose today is the subject of controversy regarding its effects on health. This sugar is found in raw foods, such as fruits (7 g of fructose in 100 g of apple, source) or honey (39 g of fructose and 31 g of glucose in 100 g of honey), their by-products such as juices, jams or syrups, but also in the form of additions in processed food products. The fructose consumed, therefore, comes from free fructose (fruit, honey), sucrose (after hydrolysis into glucose and fructose) or even glucose-fructose syrups.

1. Why use fructose?

Fructose has a relative sweetness of about 1.3. It is higher than that of sucrose, which makes up powdered or cubed sugar, and which corresponds to the standard of 1. Glucose, on the other hand, has a lower sweetening power of 0.7. Fructose is therefore considered an “intense sweetener” and is widely used in the manufacture of sodas since its sweetening power is highest when it is in acid solution and at low temperatures.

Fructose is also used in industrial food preparations for its Physico-chemical properties. It gives color and aroma, contributes to the texture of sweet foods (crispy biscuits, aeration of cake batters, diversity of texture in confectionery), increases the shelf life of jams, serves as a support for the crystallization of cocoa butter from chocolate, lowers the freezing point of water (making ice cream and sorbets), promotes yeast fermentation in bakery, etc.

The food industry mainly uses glucose-fructose syrups to provide specific properties to food (maintenance of hydration, inhibition of microbial development, browning during cooking, etc.), which depend on the relative contents of fructose and glucose...

These syrups or HFCS (high fructose corn syrup) were developed in the United States in the 1960s. Starch extracted from corn is hydrolyzed into glucose by α-amylase, which cuts the starch chains into oligosaccharides, and glucoamylase, which cuts these small chains into glucose molecules. Then glucose isomerase converts some of this glucose into fructose.

In the United States, the fructose contents of HFCS are 42% (HFCS 42) or 55% (HFCS 55). In France, the majority of glucose-fructose syrups contain between 20 and 30% fructose.

2. Fructose consumption

It was honey, which was first used as a sweetener. Sugar cane was known since prehistoric times in Asia and then travelled with humans, especially to the West Indies and South America, in the fifteenth century, when sugar became a colonial commodity at the origin of triangular trade. From the nineteenth century, the cultivation of sugar beet developed in Europe and industrialization allowed refined sugar to become a popular product.

Initially used to sweeten beverages (coffee and tea), this sugar was introduced into culinary preparations and its consumption increased considerably (by 1,500% in England between the eighteenth and nineteenth centuries). In the United States, it was 90 g per day per person in 1970. Sucrose consumption began to decline in the 1970s, as HFCS consumption increased. In the United States, the consumption of HFCS in 2004 was about 20 kg per person per year, like sucrose.

In France, the average fructose intake per person is estimated at 42 g per day. Since there are no specific data on simple carbohydrates added to the diet (half of the total intake of simple carbohydrates), this fructose intake is estimated from the average sugar intake.

Estimating fructose consumption

From an average consumption of simple carbohydrates of 100 g per day, in adults, from which 10 g of lactose is deducted, it is considered that 50% of sugar, or 45 g, is naturally present in food and 50%, or 45 g also, corresponds to added sugars. The naturally occurring sugar is estimated to contain 50% fructose or 22 g. 80% of the added sugar is sucrose, half of which is fructose, or 18 g, and 20% glucose-fructose syrup, 20% of which is fructose, or 2 g. The total fructose ingested per day is therefore estimated at 22 g + 18 g + 2 g or 42 g per day.

Fructose consumption is divided into 22 g present in fruits and honey, 18 g from sucrose and 2 g from glucose-fructose syrups added industrially to food. In the largest consumers of simple carbohydrates, fructose consumption is estimated at 77 g per day.

3. The specific treatment of fructose by the body

3.1. Two different hexoses

Fructose and glucose are two isomers: these molecules have the same crude formula, C6H12O6, but have different spatial configurations. Fructose differs from glucose by the presence of a ketone function (R-CO-R) in position 2, instead of an aldehyde function (R-CO-H) in position 1, of the carbon chain.

3.2. Specific fructose metabolism

3.2.1. At the intestinal level

Fructose present in the intestine, regardless of its food origin, is absorbed through a different process than glucose which, unlike the latter, does not involve hydrolysis of ATP and is independent of sodium absorption.

Fructose is transported into the enterocyte by facilitated diffusion through the apical membrane, thanks to a specific fructose transporter, GLUT5. Once in the enterocyte, fructose passes through facilitated diffusion to the blood capillaries thanks to another transporter, GLUT2. This one, located at the basal pole of the enterocyte, has a lower affinity for fructose than GLUT5 and is also able to support glucose.

Compared to glucose, the intestinal absorption of fructose appears relatively limited and is influenced by many factors. In particular, there are individual variations (people who absorb low fructose are prone to diarrhea and flatulence), variations related to age (decrease in this absorption with ageing), or to the environment (in rats, the synthesis of GLUT5, low before weaning, can be increased by absorption of fructose; in addition, a diet rich in saturated fatty acids increases the absorption of fructose).

Once in the enterocyte, fructose is partly converted into lactate which passes into the portal blood. This conversion represents 12% of the fructose absorbed, compared to 2% of the glucose absorbed.

3.2.2. At the hepatic level

After its absorption by the intestine, the fructose present in the portal blood is entirely taken by the liver in a single pass. It is then quickly converted into fructose-1P thanks to a specific fructose enzyme, fructokinase.

People deficient in this enzyme have fructose in the urine (fruituria), indicating that no organ other than the liver is significantly involved in fructose metabolism. After ingestion of fructose, there is only a very small increase in its concentration in the general circulation (a few micromoles per liter). Although tissues other than the liver, such as kidney and adipose tissue, have GLUT5 transporters (whose role in these cell types is not known), no tissue other than the liver expresses the enzyme fructokinase.

If fructose and glucose enter the hepatocyte through the same GLUT2 transporters, the rest of their metabolism totally differs because they are then supported by different specific enzymes. The hepatic metabolism of fructose begins with its phosphorylation to fructose-1-P thanks to fructokinase, while glucose is phosphorylated to glucose-6-P by glucokinase (or hexokinase IV, a glucose-specific enzyme also found in the islets of Langerhans).

Glucose-6-P is then transformed into fructose-6-P, which is metabolized to fructose-1,6-biP (fructose-1,6-biphosphate) by phosphofructokinase, then split into two trioses-phosphates, one of which, glyceraldehyde-3-P, will give pyruvate, source of acetyl-CoA (and citrate) and therefore, via the Krebs cycle and the respiratory chain, ATP. The conversion of glucose to pyruvate (glycolysis) is a metabolic pathway regulated positively by insulin (which stimulates the expression of the glucokinase gene) and negatively by the inhibitory retro console exerted by citrate and ATP (i.e. the energy state of the hepatocyte), on phosphofructokinase, the enzyme that catalyzes the transformation of fructose-6-P into fructose-1,6-biP.

The transformation of fructose into trioses-phosphates occurs independently of insulin and occurs rapidly, both thanks to the high affinity of fructokinase for fructose and the absence of negative feedback. Indeed, fructose enters glycolysis at the level of trioses-phosphates (dihydroxyacetone-phosphate and glyceraldehyde-3-phosphate), thus "bypassing" the essential control point of glycolysis, that is to say, the inhibition exerted by ATP and citrate on phosphofructokinase.

Fructose metabolism can thus be an "unlimited", unregulated source of glycerol-3-phosphate and acetyl-CoA for hepatic lipogenesis.

In hamsters, a diet high in fructose leads, by conversion of fructose into fatty acids in the enterocyte, an increase in the blood level of triglycerides (an effect known in rats since the 1970s), which circulate in the form of chylomicrons.

Some of the trioses-phosphates from fructose are transformed into pyruvate and enter the Krebs cycle, another part is transformed into lactate. But the majority of trioses-phosphates from fructose are converted into glucose, which can participate in the synthesis of glycogen in the liver or be dropped into the general circulation.

It should be noted that the high content of fructose-1P in the hepatocyte, which follows fructose ingestion, can act on liver glucose levels. Indeed fructose-1P is an antagonist of a protein regulating glucokinase, an enzyme that catalyzes the transformation of glucose into glucose-6P but is also involved in inhibiting the release of glucose into the blood, in case of hyperglycemia in the portal blood. Thus activated by this inhibition of its inhibitory protein, glucokinase retains more glucose in the hepatocyte. The addition of a small dose of fructose (so-called "catalytic" dose) to a dish rich in glucose, can therefore further increase the level of hepatic glucose.

4. Fate of ingested fructose in a healthy subject

In healthy subjects, after ingesting fructose, plasma glucose and insulin levels change only slightly, and fructose levels rise from 50 to 500 micromoles per liter of blood. However, there is a sharp increase in carbohydrate oxidation.

Studies that have used fructose labelled with 13C indicate that almost all of an oral load of fructose (1.33 mmol.kg-1.h-1 for 3 h, source) is metabolized at the splanchnic level (mainly in the liver but also in the intestine). About 50% passes into the bloodstream as glucose, 25% as lactate, and about 15% as hepatic glycogen. The remaining 10% is used for the production of ATP in splanchnic tissues or participates in hepatic lipogenesis.

In vitro data have shown that lactate (rather than trioses-phosphates) is a lipogenic precursor and that activation of pyruvate-dehydrogenase by a high-fructose diet is an essential step in this lipogenesis. There is also, in the circulating blood, a disappearance of non-esterified fatty acids, which indicates an inhibition of lipolysis in adipose tissue. This could be due to the low increase in insulin levels observed after ingestion of fructose, given the high sensitivity of adipocytes to this hormone, or the high level of lactate.

The administration of fructose, like glucose, increases energy expenditure but the thermal effect of fructose is higher than that due to glucose, whether it is fructose alone or fructose added to a meal. This increase in basal metabolism is explained by the high need for ATP required by fructose-induced neoglucogenesis and neolipogenesis.

5. Use of fructose in people with diabetes

Over the past two decades, numerous studies have demonstrated a relationship between, on the one hand, a high intake of carbohydrate-rich foods with a high glycemic index (or GI) or a high glycemic load (GC =GI x amount of carbohydrates) and, on the other hand, the risk of diabetes, obesity and cardiovascular disease (K. Berneis and U. Keller,  The significance of the glycemic index of foods containing carbohydrates).

In this context, fructose has two characteristics that make it a sweetener of interest for people with diabetes:

the glycemic index of fructose is very low compared to that of glucose. It is 19 against 100, by definition, for glucose, and therefore does not raise the level of glucose in the blood too much after ingestion.

it does not require the intervention of insulin, neither for its transport in the liver cell nor for the initial stages of its hepatic metabolism.

The glycemic index

The GI or glycemic index is a measure that evaluates the rate of absorption of glucose contained in food. To measure it, a person is given food containing 50 g of carbohydrates and his blood sugar is measured every half hour for 3 hours. The blood glucose curve is then compared to that obtained with a reference food, usually glucose or white bread (source). There is high individual variability and this GI also depends on the method of preparation of the food (cooking, purring, etc.). Finally, the association with proteins and/or fibers, in particular, delays the digestion of the food and lowers its glycemic index.

Fructose, when administered to diabetic patients, produces only small increases in blood sugar and plasma insulin levels, compared to what glucose would have caused, but the plasma increase in insulin levels is more pronounced than in non-diabetic subjects.

The increase in carbohydrate oxidation and gluconeogenesis, due to fructose ingestion, is, in diabetic subjects, identical to that of healthy subjects.

The increase in thermogenesis due to fructose in a diabetic subject is the same as in a healthy subject while that following glucose ingestion is weakened. This is explained by the fact that, in insulin-resistant people, the cellular metabolism of glucose is impaired, leading to thermogenesis by lower than normal glucose intake, while the hepatic metabolism of fructose is not affected.

Long-term studies, consisting of diabetic patients of providing part of the carbohydrate intake in the form of fructose, have given results lacking inhomogeneity (especially because of the diversity of protocols), only half of them note a significant drop in blood sugar. These studies also showed that fructose was associated with a significant increase in plasma triglycerides and a decrease in HDL cholesterol.

6. Use of fructose in athletes 

Energy drinks are intended to avoid a drop in blood sugar and bring a glucose supplement to the muscles providing an effort. In the case of exogenous glucose intake alone, administered as a drink, the muscle metabolism of glucose does not exceed 1.1 g / min, probably because of the saturation of transporters in the intestinal tract. But if the drink contains a mixture of glucose and fructose, the oxidation of carbohydrates by the body can increase by 40%, this being due to the involvement of different transports and metabolisms for these two oses, hepatic for fructose and muscular for glucose. It has also been reported that fructose, in moderate doses, decreases the feeling of fatigue and allows an increase in physical performance.  

Moreover, if the effects of fructose on appetite remain controversial, it would lead to a feeling of satiety lower than that provided by glucose, especially because it has a low glycemic index and hyperglycemia normally plays an important effect in the feeling of satiety. In addition, after ingestion of dishes containing fructose, the decrease in the level of ghrelin, a hormone responsible for stimulating appetite, is less pronounced than after ingestion of glucose. The rise in leptin levels ("satiety hormone") is also less pronounced. Fructose would therefore be less effective than glucose in stopping food intake. It has even been shown that the absorption of high amounts of fructose in rats leads to hepatic resistance to leptin. However, since this hormone normally causes catabolism of liver fat, the ingestion of significant amounts of fructose promotes fatty liver disease (see below). An animal model of leptin resistance shows the presence of triglyceride deposits in the liver but also the muscles, heart or islets of Langerhans.

7. Long-term effects of fructose

Different deleterious influences of fructose on the metabolism have been experimentally demonstrated.

7.1. Fructose and dyslipidemia

In healthy subjects and diabetic subjects, a high-fructose diet, for more than a week, leads to an increase in the level of total triglycerides and in the form of VLDL. This is explained by the strong synthesis of trioses-phosphates, precursors of fatty acids, induced by fructose. In addition, this sugar stimulates the expression of the transcription factor SREBP-1c, which induces the expression of lipogenesis enzymes in the liver (independent effect of insulinemia). Fructose also activates a transcription factor-binding protein (ChREBP), thereby amplifying the expression of liver enzymes such as fatty acid synthase and acetyl-CoA carboxylase.

The hyperlipidemic effect of fructose is established, a meta-analysis has shown that ingestion of more than 50 g of fructose per day (which is close to the average in the United States) leads to an increase in blood triglycerides after meals and that taking more than 100 g of fructose per day leads to an increase in fasting triglycerides.

7.2. Fructose and lipid deposition in the liver

Beyond these changes in blood lipid levels, fructose causes the deposition of ectopic fats, that is to say outside the adipocytes, especially in the liver (fatty liver) and muscles. In rats, this effect of a high-fructose diet is visible within a week. In healthy men, the intake of 1.5 g of fructose per kilogram per day (about 2 liters of soda per day) does not change the level of fat in the liver and muscle, but the administration of double this dose for a week causes a significant increase in the amount of fat in these organs.

7.3. Fructose and insulin resistance

In rats fed a high-fructose diet, an increase in hepatic triglycerides is rapidly observed, then insulin resistance, first hepatic and then, after 5 weeks, of the whole organism.

In humans, since the 1960s, it has been known that insulin resistance is linked to dyslipidemia. Insulin-resistant subjects have ectopic lipid deposits that may provide toxic metabolic derivatives (diacyl-glycerol, fatty acids-acyl-CoA, ceramides) responsible for altering intracellular insulin signalling. For example, phosphorylation of IRS-1, insulin-receptor-substrate-1 decreases the hepatic response to this hormone.

Fructose has also been shown to cause a stress response in the rat's hepatocyte involving the activation of the JNK kinase. Providing fructose in the form of honey, rich in antioxidants, prevents both the onset of this stress and the decrease in insulin sensitivity.

7.4. Fructose and acid 

Hyperuricemia is directly related to the appearance of diseases such as gout or kidney stones. It has often been noted, in studies of high-fructose diets, an increase in the level of uric acid in the blood. A fructose load leads, in fact, in the liver, a high consumption of ATP during its transformation into fructose-1P and therefore a sharp increase in AMP, leading to the synthesis of uric acid.

7.5. Fructose and hypertension

Animal studies have shown that a high-fructose diet leads to the development of hypertension. Different mechanisms have been invoked to explain this: insulin resistance and the resulting hyperinsulinemia, an increase in the activity of the orthosympathetic nervous system possibly related to hyperinsulinemia, as well as an increase in sodium reabsorption by the kidney (in rats a high-fructose diet increases the production of sodium and chlorine transporters, see V. Klein and H. Kiat,  The mechanisms underlying fructose-induced hypertension: a review). Finally, trioses-phosphates derived from fructose can be converted into methylglyoxal, a highly reactive aldehyde that can modify the functioning of L-type calcium channels, thus increasing the intracellular concentration of calcium in smooth muscles, and therefore their tone.

An analysis of 4500 people spontaneously consuming a significant amount of fructose (of the order of 75 g of fructose per day, equivalent to two and a half cans of soda) showed a relationship with a high average blood pressure value (see D. I. Jalal, G. Smits, R. J. Johnson and M. Chondral, Increased Fructose Associates with Elevated Blood Pressure). However, in an interventional study consisting of 30% overeating of energy intake in the form of fructose in healthy men, hypertension was not observed. Further data must therefore be acquired in this area.

7.6. Comparison of fructose effects and glucose effects

Supplementing overweight women with 30% of energy needs, provided in the form of glucose or fructose, resulted in the same weight gain. However, fructose resulted in higher postprandial elevations in triglycerides and LDLs, elevated hepatic lipogenesis, and decreased insulin sensitivity.

7.7. Influence of the dietary form of fructose

The total fructose measured in epidemiological studies can have different origins: simple fructose added to the diet, simple fructose consumed with glucose (ratio close to 1) in the form of glucose-fructose syrups (HFCS), or fructose associated with glucose in the form of a diose, sucrose, in sugar.

The effects of HFCS appear similar to those of fructose alone; the same response of hepatocytes, the same elevation of plasma triglycerides.

In healthy, voluntary women, HFCS and sucrose (a comparison of bound glucose-fructose and free fructose glucose) produce the same effects on glucose, insulin, ghrelin and leptin levels.

In the current state of knowledge, the effects of fructose seem identical regardless of the molecular form in which it is found in the diet.

8. Involvement of fructose in metabolic diseases

As early as 2007, the epidemiological study "Framingham Heart Study", carried out on more than 6000 people, showed that the consumption of more than one can of sugary drink per day was significantly associated with the prevalence (number of existing cases) of metabolic syndrome. In addition, in healthy subjects, this consumption of sugary drinks increases the risk of this syndrome developing (increase in the number of new cases or incidence).

Metabolic syndrome

Metabolic syndrome is defined by the presence of at least three of the following clinical features: high blood pressure, a waist circumference greater than 35 inches (89 cm) for women and 40 inches for men (101.5 cm), fasting hyperglycemia (100 mg.dl-1) as well as high triglycerides (150 mg.dl-1) and low fasting HDL-cholesterol (40 mg. dl -1 for men and 50 mg.dl-1 for women),  spring.

In a Swiss study of 74 children aged 6 to 14 years, it was shown that overweight children had a similar fructose intake to normal-weight children but consumed a higher percentage of sweets and sugary drinks. In this population, fructose intake was associated with an increase in the concentration of low-density lipoproteins (LDL, known to be linked to a high risk of atherosclerosis).

The relationship between sugar-sweetened beverages and coronary heart disease was finally demonstrated by the Nurse Health Study of 88,520 women, with much of the relationship based on the influence of body mass. The hypothesis of the influence of overweight itself on the incidence of cardiovascular risk was therefore considered, but this association remains significant after adjusting the results according to weight and may have originated from either the high glycemic index or the high fructose content of these sugary drinks.

9. Perspectives in the field of public health

To date, epidemiological studies give only incomplete and sometimes discordant results on the relationships between fructose intake and metabolic and cardiovascular diseases, due in particular to the imprecision of data on the different forms of carbohydrates consumed.

Short-term interventional studies, however, suggest that high intakes of fructose, in the form of sugary drinks, juices or pastries may increase the risk of developing this type of disease. Fructose, in high doses, has three main effects, all of which can ultimately lead to cardiovascular diseases (hypertension, atherosclerosis, etc.).

• increased calorie intake that can lead to obesity, then insulin resistance, diabetes and finally cardiovascular disease
• Insulin resistance
• dyslipidemia

In view of current knowledge, even if there is no evidence that a moderate intake of fructose, free or in the form of fruit (whose fiber limits intestinal absorption) or honey, can have harmful effects, it nevertheless seems important:

• to ensure that the intake of fructose in food, especially in the form of glucose-fructose syrups, does not increase compared to current values.
• to take into account fructose intakes in the medical follow-up of diabetic or overweight patients
• inform consumers, in particular young people, about the risk of excessive consumption of fructose, in particular in the form of sugar-sweetened beverages (aiming for maximum consumption of 50 g per day).

11. What are the health benefits?

12. Calories 

13. Fructose intolerance: what to do?