Reducing Snack Variety in Weight Loss Treatment
Condition: Obesity
MeSH terms: Obesity
Study type: Interventional

Summary: 
      The rising prevalence of obesity in the United States is believed to be due to increased
      exposure to adverse environmental factors, such as food portion sizes and increased dietary
      variety. Although decreasing portion sizes is a strategy used in weight loss programs,
      research has not studied the effects of decreasing dietary variety. Cross-sectional studies
      show a positive association between variety and body weight and in our own studies the
      investigators have shown that greater reductions in the number of different snack foods
      (i.e., cookies, chips) consumed predicted greater decreases in overall caloric and fat intake
      and greater weight loss. Limiting variety may reduce intake through long-term
      sensory-specific satiety and/or monotony. Reducing dietary variety is a novel dietary
      approach with the potential to improve long-term weight loss, which has not been studied as a
      clinical strategy in obesity research. The objective of this application is to conduct a
      randomized controlled trial of a behavioral weight loss intervention limiting the number of
      different snack foods consumed. Two hundred overweight and obese participants will be
      randomized to a standard behavioral intervention (Standard) or to a standard behavioral
      intervention that also limits the number of different snack foods consumed (Limited Variety).
      Both conditions will receive an 18-month standard behavioral intervention, using behavioral
      techniques (i.e., self-monitoring) to change eating behaviors. Participants in the Limited
      Variety condition will also limit variety in snack foods to only two chosen snack foods
      throughout the intervention. Measures of weight, snack food consumption and hedonics, and
      diet satisfaction will be taken at 0, 6, 12, and 18 months. This investigation will
      determine:

        1. if the Limited Variety condition produces greater weight loss than the Standard
           condition at 18 months;

        2. if the Limited Variety condition consumes fewer servings and calories from snack foods
           than the Standard condition;

        3. if limiting snack food variety produces long-term sensory-specific satiety and/or
           monotony.

      Relevance: Experimental studies show that limiting dietary variety profoundly reduces intake.
      To date, there is no dietary prescription that has been tested that capitalizes on the effect
      of variety on intake that can be maintained. This will be the first investigation to examine
      methods of manipulating dietary variety that can be adhered to over time and that influence
      intake, weight loss, and weight loss maintenance.
    


Intervention name(s): Standard; Limited Variety
Intervention type(s): Behavioral; Behavioral
Intervention description(s): 18-month standard behavioral weight loss intervention; Two chosen snack foods
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: Weight; Dietary intake; Energy; Hedonics; Behavioral; Sensory-specific satiety; Monotony