|Nutrition Evidence Library|
Mourao DM, Bressan J, Campbell WW, Mattes RD. Effects of food form on appetite and energy intake in lean and obese young adults. Int J Obes (Lond). 2007 Nov;31(11):1688-95. Epub 2007 Jun 19.
PubMed ID: 17579632
non-randomized group trial
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Research Design and Implementation Rating:
NEUTRAL: See Research Design and Implementation Criteria Checklist below.
To contrast the appetitive and acute compensatory dietary responses of lean and obese adults presented with comparable solid and beverage forms of high carbohydrate, high fat, or high protein foods.
Description of Study Protocol:
Individuals were recruited by public advertisement, completed and signed an informed consent for approved by the Purdue University IRB, and received monetary compensation.
Non-randomized group crossover trial
Intervention (if applicable)
120 Participants (60 lean, 60 obese) were challenged with matched beverage and solid food forms of high carbohydrate, high protein, and high fat foods. Forty different participants (N = 20 lean and 20 obese) were tested with each of the food systems. Each participant came to the lab on three test days (control, beverage, and solid). Participants were instructed to fast for 10 h overnight, eat their typical breakfast (same meal for each of the 3 test days), and fast again for at least 3 h before lunch. A finger stick glucose measurement was taken to verify pre-test fast was maintained (blood glucose <110 mg/dl). Testing visits were scheduled during participants' usual lunchtimes. At lunchtime participants were provided with chicken sandwiches ad libitum and water (control session) or chicken sandwiches ad libitum and sample foods. On test days with the sample foods mentioned, participants were instructed to eat two-thirds of the sample food, evaluate their level of fullness, and determine if eating a chicken sandwich would impede their ability to finish consuming the sample food. Pre- and post-meal, participants completed a motor skills test and an appetite questionnaire. Participants kept a food record of all food and beverages consumed until the end of the test day, as well as completing the appetite questionnaire via Personal Digital Assistant each hour until the end of the test day.
Repeated measures analysis of variance with one within - subject factor (meal form - beverage and solid) and one between-subject factor (lean vs obese). 20 participants per group (lean vs obese) needed for 80% power.
Data Collection Summary:
Timing of Measurements
Testing visits were scheduled during participants' usual lunchtimes. On test days participants kept a food record of all foods and beverages consumed before going to sleep and completed an appetite questionnaire on a PDA (given to them) each hour until going to sleep.
Description of Actual Data Sample:
Initial N: 120 lean (N=60) and obese (N=60) participants
Attrition (final N): none mentioned
Age: 18 - 50 years
Ethnicity: not specified
Participants in the lean group had a BMI between 18 - 23 kg/m2, while participants in the obese group had a BMI between 30 - 35 kg/m2.
Location: Indiana, United States
Summary of Results:
Summary of Key Findings:
Calorie intake for the whole day was significantly greater for all three groups (high protein, high carbohydrate, and high fat) when the beverage form of the food was consumed in a lunch meal, compared with the solid form of the food. The beverage form of all three groups resulted in reverse compensation, meaning that daily calorie intake was greater than baseline by an amount that exceeded the calories in the beverage. In comparison, there was partial to overcompensation for the solid foods, meaning that calorie intake was lower than baseline. There was no clear indication that this differs between lean and obese individuals. Because having high protein, high carbohydrate, and high fat beverages with lunch all led to consuming more calories than would be consumed on a typical day, efforts to moderate energy intake should consider the contribution of all types of beverages.
A major limitation of this study is its small sample size and its exclusion of participants with a BMI between 23.1 and 29.9 kg/m2, as well as those with a BMI greater than 35 kg/m2. The small sample size and exclusion factors limits the generalizability of these results. In addition, dietary compensation was only observed for one day, and daily intake is highly variable. Another limitation is that only three foods were tested, and these foods do not represent all facets of products and their modulating affect on consumption.
Copyright American Dietetic Association (ADA).