Altering the temporal distribution of energy intake with isoenergetically dense foods given as snacks does not affect total daily energy intake in normal-weight men

Abstract

The objectives of the present study were to examine the effects of (1) ingesting mandatory snacks v. no snacks and (2) the composition of isoenergetically-dense snacks high in protein, fat or carbohydrate, on food intake and energy intake (EI) in eight men with ad libitum access to a diet of fixed composition. Subjects were each studied four times in a 9 d protocol per treatment. On days 1–2, subjects were given a medium-fat maintenance diet estimated at 1·6 × resting metabolic rate (RMR). On days 3–9, subjects consumed three mandatory isoenergetic, isoenergetically dense (380 kJ/100 g) snacks at fixed time intervals (11.30, 15.30 and 19.30 hours). Total snack intake comprised 30 % of the subjects' estimated daily energy requirements. The treatments were high protein (HP), high carbohydrate (HC), high fat (HF) and no snack (NS). The order was randomized across subjects in a counterbalanced, Latin-square design. During the remainder of the day, subjects had ad libitum (meal size and frequency) access to a covertly manipulated medium-fat diet of fixed composition (fat: carbohydrate: protein, 40:47:13 by energy), energy density 550 kJ/100 g. All foods eaten were investigator-weighed before ingestion and left-overs were weighed after ingestion. Subjective hunger and satiety feelings were tracked hourly during waking hours using visual analogue scales. Ad libitum EI amounted to 13·9 MJ/d on the NS treatment compared with 11·7, 11·7 and 12·2 MJ/d on the HP, HC and HF diets respectively (F(3,21) 5·35; P = 0·007, sed 0·66). Total EI values were not significantly different at 14·6, 14·5, 15·0 and 14·2 MJ/d respectively. Snack composition did not differentially affect total daily food intake or EI. Average daily hunger was unaffected by the composition of the snacks. Only at 12.00 hours did subjects feel significantly more hungry during the NS condition, relative to the other dietary treatments (F(3,18) 4·42; P = 0·017). Body weight was unaffected by dietary treatment. In conclusion, snacking per se led to compensatory adjustments in feeding behaviour in lean men. Snack composition (with energy density controlled) did not affect the amount eaten of a diet of fixed composition. Results may differ in real life where subjects can alter both composition and amount of food they eat and energy density is not controlled.

Testing Protein Leverage in Lean Humans: A Randomised Controlled Experimental Study

“…The idea that protein influences energy intake through hunger would also help to explain results from studies showing that mandatory high protein snacks are energetically compensated for at subsequent ad libitum meals but do not reduce total energy intake over a day [36], [37], and that eating a high-protein snack prolongs the time until a subsequent request for dinner [38]. Interestingly, the mean hourly hunger levels of participants across the entire day in the current study did not differ between dietary treatments.…”

Weighing the Evidence of Common Beliefs in Obesity Research

“…Palmer and others in 2009 reviewed the association between eating frequency and body weight 335 , from which we identified 6 experiments that looked directly at snacking and weight 271,292,330,344-346 . In Table 1, we include those 6 studies, plus three more that were reported after their review 347-349 .…”

“…In Table 1, we include those 6 studies, plus three more that were reported after their review 347-349 . Studies were as short as 9 days 344 to as long as 1 year 330 , and include several different study designs, snacking patterns, and types of snacks. In none of these studies was a difference detected between the snacking versus the non-snacking study arms with respect to measurements of obesity including weight, weight change, BMI, body fat percentage, waist circumference, or waist to hip ratio.…”

Comparing the Nutritional Impact of Dietary Strategies to Reduce Discretionary Choice Intake in the Australian Adult Population: A Simulation Modelling Study

“…A 50% reduction in energy from all discretionary choices would bring the population mean intake close to the top of national nutrition guidelines of 0–1800 kJ (~15% of total energy intake) per day [37]. To account for possible energy compensation [38,39], sensitivity analyses tested a lower and upper bound energy compensation with interquartile ranges of 25% and 75% replacement of energy with all core and discretionary foods. Energy compensation was based on observed base case intake distribution of core and discretionary foods to total energy intake (see Table S1).…”