Our body is a very complex machine that is governed by several physiological mechanisms. Is it possible to fool our brain and our hunger signals by consuming anorectic foods or appetite suppressants? These foods have, according to belief, a satiating power that can suppress hunger. Is this a zany new cure for weight loss, or do these foods really exist?
What influences food intake
Hunger and fullness are among the main factors that influence our food intake. Satiety is the period of time between two meals when hunger is not felt. Depending on the blood sugar level, fat reserves and accessibility to food in the immediate environment, there will either be a feeling of hunger or a feeling of satiety. The more we ingest large quantities of food, the more feelings of fullness will set in. Did you know that a meal’s calorie content could influence the amount of food eaten during the rest of the day? Contrary to what one might think, a large meal, very high in calories, provides a low level of satiety and, for this reason, would encourage overconsumption.
Are there some nutrients that are more satiating than others?
Lipids (or fats) are the least anorectic macronutrients. Consequently, a diet high in fat will not suppress hunger. On the contrary, high lipid intake may lead to overeating, which could lead to weight gain. The most satiating nutrient is protein. However, not all proteins have the same appetite-suppressing effect! Depending on their chemical structure, proteins have a different speed of digestion and absorption. The slower the speed of digestion, the greater protein’s satiating power.
Lysine, leucine, and phenylalanine are amino acids - small compounds that form the basis of proteins - with the ability to quickly trigger the insulinemic response. This means that the normalization of blood sugar will be faster and the feeling of hunger may return earlier. These amino acids don’t have a high anorectic effect. On the other hand, certain residues of protein digestion stimulate the production of anorectic hormones: cholecystokinin (CCK) and glucagon-like-peptide-1 (GLP-1). These hormones have an impact on reducing hunger. In short, the impacts on hunger are very varied from one protein to another!
The glycemic index’s influence on our hunger
The glycemic index of food may have an effect on our appetite. The glycemic index represents the rate at which a food’s carbohydrates are digested and converted into glucose. This sugar is the brain's preferred energy substrate, which uses it for energy. The higher a food’s glycemic index, the more the carbohydrates in that food have the potential to rapidly raise blood sugar. Consequently, foods with a lower glycemic index have a stronger satiating power than foods with a high glycemic index, because their digestibility is slower, which may even increase their satietogenic effect.
It’s important to know that different factors can influence the glycemic index. In fact, the high contents of fibres, proteins and lipids of a food or a meal reduce the glycemic index and slow down the speed of digestion. In summary, foods high in fibre, protein and fat last longer in the postprandial state, which is the time after a meal. The type of cooking and processing of food may also influence the glycemic index. For example, heating a food to a high temperature will change its structure, which can make it more easily digestible by enzymes and, therefore, less satiating. In addition, actions, such as "cutting," "crushing" or "crumbling" can easily improve food absorption and make a dish less filling. This example is easily explained with potatoes. Potato wedges have a lower glycemic index than mashed potatoes which, in turn, have a higher glycemic index.
Does calorie content matter?
A food’s energy density - the number of calories that it provides according to its weight - is thought to play a role in satiety. Foods with a lower energy density, such as fruits and vegetables, are those with a stronger satietogenic effect. Food volume could be the cause. Fruits and vegetables can occupy a large volume for a low calorie intake. One study showed that a diet with high intakes of fruits and vegetables and low in fat would lead to weight loss or weight maintenance in participants. The researchers attribute this effect to the energy density of foods, but don’t rule out that the total amount of calories, the water content of foods or the presence of dietary fibre in fruits and vegetables could also have a positive effect on body weight.
Finally, are there any foods with the ability to supress the appetite? Yes and no! In fact, certain nutrients like protein and fibre sustain longer and provide a feeling of prolonged satiety unlike large, high-fat meals. Additionally, fruits, vegetables, and foods with a lower glycemic index that have undergone the least handling and cooking are just a few good examples of appetite-inducing foods.
Familiprix in collaboration with Hubert Cormier