Effects of macronutrient content and energy density of snacks consumed in a satiety state on the onset of the next meal.
ABSTRACT We examined the effects of nutrient composition of a 1 MJ afternoon snack, consumed in a satiety state, on the spontaneous onset of the next meal in 11 young male subjects deprived of any temporal cues. All subjects attended four experimental sessions scheduled 2 weeks apart. The first, baseline, session served to establish: (1) the subjects' ad libitum lunch intake, (2) the latency of the spontaneous request for dinner following lunch, (3) ad libitum food intake at dinner. Lunches provided during the next three sessions were based on baseline lunch intakes. During the following three sessions, conducted in counterbalanced order, subjects were given a high-fat (58% of energy from fat), a high-protein (77%) or a high-carbohydrate (84%) snack to be consumed 240 min after the beginning of lunch. Latency to dinner and the amount of energy consumed at dinner were two dependent variables. Consumption of a high-protein snack delayed the request for dinner by 60 min. In contrast, high-fat snack delayed dinner request by 25 min, whereas high-carbohydrate snack delayed dinner request by 34 min. Snack composition had no impact on energy or macronutrient intakes during dinner.
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ABSTRACT: Energy intake is a function of the quantity of energy consumed per ingestive event and the number of these events. The marked increase of energy intake and body weight over the past 35years indicates there has been poor precision in the reciprocity of these two facets of intake. With recent study of the associations between gut "satiation" peptides and energy intake, there has been an emphasis on the contribution of portion size to positive energy balance. However, this orientation may not appropriately weight the contribution of ingestive frequency. Gut peptides are not purely satiation factors and metabolic and environmental cues may more strongly guide the onset and number of ingestive events. Evidence is presented that while both portion size and ingestive frequency have increased in the population, the latter may be more problematic for weight gain. The magnitude and time course of increments in ingestive frequency better map onto energy intake and BMI trends than changes of portion size. This may occur, in part, because dietary compensation and thermogeinic effects are weaker for increases in ingestive frequency than portion size. Though not to the exclusion of consideration of portion size effects, improved weight management may be achieved with greater attention to the drivers of eating and drinking frequency.Physiology & Behavior 11/2013; · 3.16 Impact Factor
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ABSTRACT: Previous research suggests that monosodium glutamate (MSG) may have a biphasic effect on appetite, increasing appetite within a meal with its flavour-enhancing effect, but enhancing subsequent satiety due to its proposed role as a predictor of protein content. The present study explored this by assessing the impact of a 450 g soup preload differing in MSG concentration (1 % MSG added (MSG+) or no MSG (MSG–)) and nutrient content (low-energy control or high-energy carbohydrate or high-energy protein) on rated appetite and ad libitum intake of a test meal in thirty-five low-restraint male volunteers using a within-participant design. Protein-rich preloads significantly reduced intake at the test meal and resulted in more accurate energy compensation than did carbohydrate-rich preloads. This energy compensation was stronger in the MSG+ protein conditions when compared with MSG+ carbohydrate conditions. No clear differences in rated appetite were seen in MSG or the macronutrient conditions alone during preload ingestion or 45 min after intake. Overall, these findings indicate that MSG may act to further improve energy compensation when provided in a protein-rich context.Journal of Nutritional Science. 08/2014; 3:e15.
Article: Protein leverage and energy intake.[Show abstract] [Hide abstract]
ABSTRACT: Increased energy intakes are contributing to overweight and obesity. Growing evidence supports the role of protein appetite in driving excess intake when dietary protein is diluted (the protein leverage hypothesis). Understanding the interactions between dietary macronutrient balance and nutrient-specific appetite systems will be required for designing dietary interventions that work with, rather than against, basic regulatory physiology. Data were collected from 38 published experimental trials measuring ad libitum intake in subjects confined to menus differing in macronutrient composition. Collectively, these trials encompassed considerable variation in percent protein (spanning 8-54% of total energy), carbohydrate (1.6-72%) and fat (11-66%). The data provide an opportunity to describe the individual and interactive effects of dietary protein, carbohydrate and fat on the control of total energy intake. Percent dietary protein was negatively associated with total energy intake (F = 6.9, P < 0.0001) irrespective of whether carbohydrate (F = 0, P = 0.7) or fat (F = 0, P = 0.5) were the diluents of protein. The analysis strongly supports a role for protein leverage in lean, overweight and obese humans. A better appreciation of the targets and regulatory priorities for protein, carbohydrate and fat intake will inform the design of effective and health-promoting weight loss diets, food labelling policies, food production systems and regulatory frameworks.Obesity Reviews 03/2014; 15(3):183-91. · 6.87 Impact Factor