Effect of reducing portion size at a compulsory meal on later energy intake, gut hormones, and appetite in overweight adults

Large food portions may be facilitating excess energy intake (EI) and adiposity among adults. The present study aimed to assess the extent to which EI and amounts of foods consumed are influenced by the availability of different-sized food portions. A randomised within-subject cross-over, fully residential design was used, where forty-three (twenty-one men and twenty-two women) normal-weight and overweight adults were randomly allocated to two separate 4 d periods where they were presented with either ‘standard’ or ‘large’ food portions of the same foods and beverages. The main outcome measures were the amount of food (g) and EI (MJ) consumed throughout each study period. Mean EI over 4 d was significantly higher on the large portion condition compared with the standard condition in the total group (59·1 (sd 6·6) v. 52·2 (sd 14·3) MJ; P = 0·020); men and women increased their EI by 17 % (10 (sd 6·5) MJ; P < 0·001) and 10 % (4 (sd 6·5) MJ; P = 0·005) respectively when served the large food portions relative to the standard food portions. The increased intakes were sustained over the 4 d in the large portion condition with little evidence of down-regulation of EI and food intake being made by subjects. Increased food portion size resulted in significant and sustained increases in EI in men and women over 4 d under fully residential conditions. The availability and consumption of larger portions of food may be a significant factor contributing to excess EI and adiposity.

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Faculty Opinions recommendation of Reductions in portion size and energy density of foods are additive and lead to sustained decreases in energy intake.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.11448.468933 ◽

2006 ◽

Author(s):

Bruce Bistrian

Keyword(s):

Energy Density ◽

Energy Intake ◽

Portion Size

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A universal driver of human eating behaviour? Individual differences in energy intake in response to reducing main meal portion size

Appetite ◽

10.1016/j.appet.2020.104892 ◽

2020 ◽

pp. 104892

Author(s):

Eric Robinson ◽

Ashleigh Haynes

Keyword(s):

Individual Differences ◽

Energy Intake ◽

Eating Behaviour ◽

Portion Size ◽

Main Meal

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Mechanisms behind the portion size effect-visibility and bite size

10.31232/osf.io/6spb7 ◽

2017 ◽

Author(s):

Kyle Stanley Burger ◽

Susan L. Johnson

Keyword(s):

Size Effect ◽

Energy Intake ◽

Repeated Measures ◽

Visual Cues ◽

Normal Weight ◽

Portion Size ◽

Experimental Conditions ◽

Bite Size ◽

Subject Design ◽

Participant Characteristics

Increases in portion size lead to increases in energy intake, yet the mechanisms behind this ‘portion size effect’ are unclear. This study tested possible mechanisms of the portion size effect i.e., bite size and visual cues in 30 over- and normal-weight individuals (15 men, 15 women). A 2x2 repeated measures, within-subject design was used to test the effects of portion size (410g vs. 820g of a pasta dish) and visual cues (blindfolded vs. visible) on energy intake. At each meal participants were exposed to one of four experimental conditions (small portion/visible; small portion/blindfold; large portion/visible; large portion/blindfold). Participant characteristics, food intake, number of bites, meal duration, palatability measures and hunger and fullness were assessed. In response to a doubling of the portion presented, entrée energy intake increased 26% (220kcal P < 0.001) and mean bite size increased 2.4g/bite (P < 0.05). Overweight individuals consumed 40% (334kcal) more of the entrée in response to the large portion condition (P < 0.05), while lean individuals’ intakes did not differ (P < 0.56). A 12% (122kcal) decrease in entrée intake was observed in the blindfolded condition (P < 0.01), but no portion by visual cue interaction was found; indicating that blindfolding did not attenuate the portion size effect. These data suggest that the portion size effect is greater in overweight individuals and occurs via changes in bite size.

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