Satiety, weight management and foods

Obesity is becoming an increasing health problem. It is a major burden for healthcare costs because it is related to many chronic diseases such as type 2 diabetes, elevated blood pressure and cardiovascular disease. Body weight is determined by a complex interaction of genetic, environmental and psychosocial factors. Obesity results when energy intake exceeds energy expenditure. Food has a crucial role in weight management. The new EU legislation on nutrition and health claims permits the use of weight regulation related health claims on foods, if they are based on generally accepted scientific evidence. In this literature review the current knowledge on food properties and potential biomarkers, that have been proposed to affect satiety and/or energy expenditure and thus might be useful in weight control are considered regarding the scientific evidence behind different factors. The short-term regulation of food intake is mediated via neural and humoral signals from GI tract to different regions in brain. Different macronutrients, carbohydrates, protein, fibre and fat, affect the release of satiety related peptides from stomach and different parts of intestine. For example, the release of glucacon-like peptide 1 (GLP-1) and peptide YY (PYY) from the intestine after meal increase satiety. In the long-term regulation of food intake the hormones leptin from adipose tissue and insulin from the pancreas play a significant role. There is no single, standard method to measure satiety. Different methods have been used in measuring sensations related to the promotion and inhibition of eating, such as satiety, appetite, hunger and fullness. Generally satiety has been measured by rating subjective feelings before and after consumption of a test food/meal, and/or by measuring the energy intake after the test food/meal. A visual analogue scale is the most commonly used method to assess subjective ratings of satiety. In the scale the end points are verbally anchored, e.g. “I’m extremely full” and “I’m not at all full”. If the satiety related feelings are rated e.g. for 120 min after ingestion of the food at certain intervals, a graph can be drawn as a function of time, and the area under the curve can be used as a measure of e.g. fullness produced by the meal/food. Satiety index and satiety quotient help in the comparison of satiety values of different foods. The search for the physiological biomarkers of appetite is active at the moment, but so far no clear winner has been found.