Study Overview
Published: Current Developments In Nutrition
Category: Type 2 Diabetes
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Background:
Few studies have explored the effect of a single food intervention on the dietary glycemic index (GI) and glycemic load (GL) within the context of a habitual diet. Avocados are low in carbohydrates, but rich in monounsaturated fatty acids, fiber, and other bioactive compounds. This raises the question of whether eating one avocado a day could lower the GI and GL of the diet, potentially reducing cardiometabolic risk.
Objective:
To assess whether adding one large avocado (168 g) daily for 6 months to the habitual diet of adults with abdominal obesity reduces dietary GI and/or GL.
Methods:
This secondary analysis used data from the Habitual Diet and Avocado Trial (HAT), a multicenter, randomized, parallel-arm study involving 1,008 adults with elevated waist circumference. Participants were randomized to either an avocado-supplemented group, instructed to consume one large avocado daily with their usual diet, or a control group who maintained their habitual diet and avoided avocados. Dietary intake was assessed via three unannounced 24-hour dietary recalls over the 6-month period, from which dietary GI and GL were calculated using Nutrition Data System for Research software. Linear regression models adjusted for age, sex, BMI, energy intake, race, ethnicity, education level, and study site were used to evaluate between-group differences.
Results:
Among 961 participants with complete data (73% women, mean age 50.5 years), the avocado-supplemented group showed a reduction in dietary GL by 13.7 points (95% confidence interval, CI: 17.0 to 10.4; p<0.001) compared to the control. Food groups contributed similar amounts to the overall GL, except for avocado.
Conclusions:
Daily consumption of one avocado within the habitual diet significantly reduced GL by almost 14 points, without requiring significant dietary changes. This suggests that incorporating a single nutrient-dense food like avocado can effectively improve the GL simply and sustainably. This trial is registered at clinicaltrials.gov as NCT03528031
