Larger portion sizes lead to a sustained increase in energy intake over 2 days.
OBJECTIVE
We tested the effect on energy intake of increasing the portion size of all foods and beverages served over 2 consecutive days.


METHODS
The study used a randomized crossover design.


METHODS
Subjects were 32 adults from a university community.


METHODS
For 2 consecutive days in each of 3 weeks, subjects ate their main meals in a controlled setting and were given snacks for consumption between meals. We used the same two daily menus each week, but varied the portion sizes of all foods and beverages served in a given week (either 100%, 150%, or 200% of baseline amounts).


METHODS
Energy intake and ratings of hunger and satiety were measured.


METHODS
A linear mixed model with repeated measures was used.


RESULTS
There was a significant effect of portion size on energy intake in both men and women (P<0.0001). Increasing portions by 50% increased daily energy intake by 16% (women: 335 kcal/day; men: 504 kcal/day), and increasing portions by 100% increased intake by 26% (women: 530 kcal/day; men: 812 kcal/day). Energy intake did not differ between the 2 days of each week. Daily ratings of fullness were lowest in the 100% portion condition (P=0.0004), but did not differ significantly in the 150% and 200% conditions.


CONCLUSIONS
Increasing the portion size of all foods resulted in a significant increase in energy intake that was sustained over 2 days. These data support suggestions that large portions are associated with excess energy intake that could contribute to increased body weight.
Department of Nutritional Sciences, The Pennsylvania State University, 226 Henderson Bldg, University Park, PA 16802-6501, USA.
Barbara J
BJ
Rolls
Liane S
LS
Roe
Jennifer S
JS
Meengs
D000328:Adult; D018592:Cross-Over Studies; D004032:Diet; D004041:Dietary Fats / Q000008:administration & dosage; D004435:Eating / Q000502:physiology*; D002149:Energy Intake / Q000502:physiology*; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D009753:Nutritive Value; D009765:Obesity / Q000453:epidemiology / Q000209:etiology*; D012527:Satiation / Q000502:physiology*; D015430:Weight Gain / Q000502:physiology*
D004041:Dietary Fats