Effect of fructose on body weight in controlled feeding trials: a systematic review and meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of controlled feeding trials
PubMed 22351714 · doi:10.7326/0003-4819-156-4-201202210-00007
What was done
Reviewers searched MEDLINE, EMBASE, CINAHL, and the Cochrane Library through November 18, 2011, for controlled feeding trials lasting 7 or more days evaluating the effect of free fructose on body weight. Trials were categorized into isocaloric trials (free fructose vs. nonfructose carbohydrate in diets with similar calories) and hypercaloric trials (diets supplemented with free fructose to provide excess energy vs. control diets). Studies evaluating high-fructose corn syrup were excluded. Data extraction and quality assessment via the Heyland Methodological Quality Score were performed independently by at least three reviewers.
What was found
Thirty-one isocaloric trials (637 participants) showed no significant effect of fructose on body weight compared to nonfructose carbohydrates (mean difference: -0.14 kg [95% CI, -0.37 to 0.10 kg]). Ten hypercaloric trials (119 participants) providing high-dose fructose (+104 to 250 g/d, +18% to 97% of daily energy intake) showed a significant increase in weight (mean difference: 0.53 kg [95% CI, 0.26 to 0.79 kg]).
Why it matters
This meta-analysis suggests that fructose does not uniquely drive weight gain compared to other carbohydrates when calories are matched, implying that weight gain from high-fructose diets is primarily attributable to excess caloric intake rather than fructose itself.
Limits
Included trials were mostly small (<15 participants), short in duration (<12 weeks), and of low methodological quality. Hypercaloric trials could not isolate the specific effect of fructose from the confounding effect of positive energy balance, and studies on high-fructose corn syrup were excluded.
Cited by
- supports When caloric intake is controlled, meta-analyses of randomized trials substituting sugars or sugar-sweetened beverages isocalorically for other carbohydrates show no differences in fat mass, body weight, or inflammation.