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NutrInsight • Satiety: from appetite sciences to food application
1.5 What are the drivers of hunger and energy intake? A new formulation of Appetite Control
The meal pattern is constituted of various eating episodes distributed over the waking hours. Hunger sensations oscillate over the day, with highest values observed before meals and lowest values immediately after meals. The ultimate drivers for this highly predictable pattern of daily eating events have been the object of much scientific research over the years. The concept of body weight regulation implies that a biological mechanism exerts control over food intake and energy expenditure. However the source and identity of the controlling mechanism have not been identified. It has been suggested that the source of this mechanism is some signal related to body fat, such as leptin.
Within the concept of energy homeostasis, it is intuitive that the body’s need for energy should be a significant driver of food intake. Importantly, the body fat free mass (FFM) is the largest contributor to the resting metabolic rate (RMR), and RMR is normally the largest component of total energy expenditure. It therefore seems plausible that FFM, RMR or both, should be related to the amount of energy that is taken in. Such a relationship could be demonstrated provided daily energy intake and meal size could be measured accurately alongside RMR and body composition.
Recent experimental works suggest that some signal associated with the lean body mass (but not the fat mass) exerts a determining effect over self-selected food consumption [Blundell et al., 2012]. In two separate intervention projects carried out in obese individuals, the relationship between variables of energy expenditure and measures of appetite control was assessed. The methodology included systematic measurements of imposed physical activity together with objectively and accurately monitored self-determined meals and daily energy intake throughout a 12-week intervention period.
Figure 3: Scatter plots and standardised-coefficients to illustrate the relationship between fat mass (FM), fat-free mass (FFM), and BMI and objectively measured daily energy intake at baseline (week 0, before exercise) and after 12 weeks of imposed exercise. a-c: week 0; d-f: week 12.
Source: Blundell et al., 2012
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