Increasing Fruits & Vegetables In Diet May Not Lead To Weight Loss

Kathryn A. Kaiser, Ph.D. Department of Biostatistics Ryals Public Health Bldg, University of Alabama at Birmingham Birmingham, AL 35294MedicalResearch.com Interview with:
Kathryn A. Kaiser, Ph.D.
Department of Biostatistics
Ryals Public Health Bldg,
University of Alabama at Birmingham
Birmingham, AL 35294

MedicalResearch: What are the main findings of the study?

Dr. Kaiser: Recommendations to increase or home delivery of fruits and vegetables to increase intake results in no significant weight loss or gain in adults studied over 8-16 weeks.

MedicalResearch: Were any of the findings unexpected?

Dr. Kaiser: We expected to find more studies that have looked at this question in well-controlled, randomized experiments, but found only seven trials in a total of just over 1200 participants. It appears some compensation from the added food is occurring because there was no significant weight gain observed.

MedicalResearch: What should clinicians and patients take away from your report?

Dr. Kaiser: There appear to be no risks for weight gain in adults who add more fruits and vegetables to their diets, but conversely, expectations for weight loss are not supported by these data. The presently available data are just too sparse to draw firm conclusions in either direction. Fruits and vegetables contain many nutrients that may hold varied health benefits.  If intake is to be increased, it must be done in the context of an energy balanced diet.  That is, the energy they contribute must be offset by reductions of energy intake from other foods or beverages.  This may not occur spontaneously so counseling may be advisable for those wishing to lose weight.

MedicalResearch: What recommendations do you have for future research as a result of this study?

Dr. Kaiser: More long term studies on different food forms (liquid versus solid) and their associated satiety properties are needed to identify whether there are combinations of foods and beverages that result in less hunger at a lower total energy level that would increase the likelihood of weight loss.

MedicalResearch: Are there any ‘big picture’ messages we can take away from this?

Dr. Kaiser: Yes. The areas of obesity and weight control seem to be one in which much misinformation is spread, often with the best of intentions, on the basis of very flimsy data, and sometimes even in opposition to the available data. The public can help protect themselves from such misinformation by always asking “What is the evidence for that?” and “How strong is that evidence?” when presented with messages. And, scientists, academics, government regulators, and public health experts need to be more diligent about assuring that our public messages are accurate and consistent with the evidence.

 Citation:

Increased fruit and vegetable intake has no discernible effect on weight loss: a systematic review and meta-analysis –

Kathryn a Kaiser, Andrew W Brown, Michelle M Bohan Brown, James M Shikany, Richard D Mattes, and David B Allison. 
American Journal of Clinical Nutrition, June 2014 DOI: 10.3945/ajcn.114.090548