The Study
Low-Energy Dense Potato- and Bean-Based Diets Reduce Body Weight and Insulin Resistance: A Randomized, Feeding, Equivalence Trial
This study gave two groups of people different diets — one with lots of potatoes and one with lots of beans — and saw what happened to their weight and blood sugar. Because they randomly assigned who got which diet, we can say the diets probably caused the changes, not just that people who ate potatoes were already healthier.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Scientists gave people with insulin resistance two different diets: one with lots of potatoes and one with lots of beans. Both diets were low in calories per bite and had the same amount of carbs, fat, and protein.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 578 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Losing 4–6% of body weight and improving insulin resistance by 1.3–1.4 units is meaningful—it’s similar to benefits seen with other healthy diets.
- 2Potatoes didn’t hurt, and worked just as well as beans.
- 3People lost weight on both diets (about 4–6% of body weight).
- 4Their insulin resistance improved by about 1.3–1.4 points on HOMA-IR.
- 5Only the bean diet lowered insulin levels after eating.
- 6Fasting blood sugar didn’t change.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of Medicinal Food
Year
2022
Authors
Candida J. Rebello, R. Beyl, F. Greenway, Kelly C Atteberry, K. Hoddy, J. Kirwan
Related Content
Claims (5)
In young people, insulin resistance and obesity develop as a result of long-term consumption of high-calorie, low-nutrient foods and low levels of physical activity.
In adults with insulin resistance, eating a low-energy-density diet rich in potatoes or beans for 8 weeks does not change fasting blood glucose levels, even though insulin sensitivity and body weight improve.
In adults with insulin resistance, an 8-week diet low in energy density and high in potatoes results in a 5.6% reduction in body weight and improved insulin resistance measured by HOMA-IR, with no difference in outcomes compared to a similar diet high in beans.
In adults with insulin resistance, eating a diet low in energy density and high in beans for 8 weeks lowers insulin response after a meal by 2136 mg/[dL·min] and improves HOMA-IR by 1.4 units compared to eating a similar diet high in potatoes.
In adults with insulin resistance, eating a low-energy-density diet high in potatoes or beans for 8 weeks lowers body mass index by 1.3 to 2.0 kg/m², and both diets produce the same reduction.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.