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Larger Portion Sizes Lead to a Sustained Increase in Energy Intake Over 2 Days

https://doi.org/10.1016/j.jada.2006.01.014Get rights and content

Abstract

Objective

We tested the effect on energy intake of increasing the portion size of all foods and beverages served over 2 consecutive days.

Design

The study used a randomized crossover design.

Subjects/setting

Subjects were 32 adults from a university community.

Intervention

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).

Main Outcome Measures

Energy intake and ratings of hunger and satiety were measured.

Statistical Analyses Performed

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.

Section snippets

Subjects

Subjects were recruited by notices in flyers and newspapers in the university community. Potential subjects were interviewed by telephone to ensure they met the following criteria: nonsmoking adults in good health between age 19 and 45 years, not dieting to gain or lose weight, not in athletic training, not pregnant or breastfeeding, not taking medications known to affect appetite, no food allergies or dislikes for the entrées and desserts served in the study, and regularly consuming three

Energy Intake

Total energy intake for the 2 days increased as portion size increased in both women and men (Figure 2;P<0.0001). In the baseline condition of portion size, women consumed 64% and men consumed 77% of the energy in the food and snacks that they were served. Baseline energy intakes did not differ significantly from estimated energy requirements; intake was a mean of 104% of energy needs. When portions were increased by 50% above baseline amounts, energy intake increased by 16% (335 kcal/day for

Discussion

This study demonstrates that increasing the portion size of all foods and beverages results in an increase in energy intake beyond physiologic requirements that is sustained over 2 days. A 50% increase in portion sizes led to a 16% increase in energy intake (669 kcal over 2 days for women; 1,059 kcal over 2 days for men), and a 100% increase in portion sizes led to a 26% increase in intake (1,009 kcal over 2 days for women; 1,624 kcal over 2 days for men). Larger portions led to increased

Conclusions

The results of this study show that increasing the portion size of all foods and beverages results in an increase in energy intake that is sustained over 2 days, with no evidence of an adjustment in food consumption over this time. The effect of increased portion size has the potential to lead to intake that is substantially in excess of energy needs in the short term, even if some compensation may occur over the longer term. Increased portion size is only one of many influences in the eating

B. J. Rolls is a professor and the Guthrie Chair in Nutritional Sciences, L. S. Roe is a research nutritionist, and J. S. Meengs is a laboratory manager, Department of Nutritional Sciences, The Pennsylvania State University, University Park.

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B. J. Rolls is a professor and the Guthrie Chair in Nutritional Sciences, L. S. Roe is a research nutritionist, and J. S. Meengs is a laboratory manager, Department of Nutritional Sciences, The Pennsylvania State University, University Park.

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