Those Who Consume Diets Meeting the Acceptable Macronutrient Distribution Range for Carbohydrate Are More Likely to Meet Dietary Fiber Recommendations: The POUNDS LOST Study (P08-085-19)
Abstract Objectives This study tested whether dietary carbohydrate intake influenced subjects’ ability to meet dietary fiber goals. Methods The POUNDS LOST study was a randomized clinical trial that examined the effects of four, calorie-restricted diets of varying macronutrient composition on weight loss in subjects with overweight or obesity. The macronutrient composition of the diets were either low or high fat (LF 20%; HF, 40%) and either average or high protein (AP, 15%; HP, 25%). This provided a graded carbohydrate intake of 35%, 45%, 55% or 65%. Energy content of each diet was 750 kcal below energy needs and each diet provided ≥20 g/d of dietary fiber. Participants (n = 345) who provided complete dietary recalls at baseline and 6-month follow-up were included in the analyses. The dietary fiber goal was defined as ≥20 g/d. Logistic regression analysis modeled the odds of meeting the dietary fiber goal and Adequate Intake (AI) for dietary fiber as a function of diet prescription while controlling for age, race, gender, and energy intake. A p-value of < 0.01 was statistically significant. Results Participants were 86.5% white and 43.9% female. Mean age was 52.7 + 8.7y. One hundred sixty-eight (48.7%) subjects met their dietary fiber goals and 146 (42.3%) met the AI for fiber at 6 months. The results from the logistic regression indicated the odds of a subject meeting their dietary fiber goals were 4.9 times greater (P < 0.0001) for the high carbohydrate (65%) diet compared to the 35% carbohydrate diet. Similarly, the odds of a subject meeting the AI for dietary fiber were 5.3 times greater (P < 0.0001) for the 65% carbohydrate diet compared to the 35% carbohydrate diet. Those randomized to either the 45% or 55% carbohydrate diets also had greater odds of meeting dietary fiber goals and the AI for dietary fiber compared to the 35% carbohydrate diet (P < 0.01). Conclusions Calorie-restricted diets are an effective approach for weight loss; however, diets should be designed to minimize the risk for inadequate nutrient intake. These results indicate that those who consumed a diet lower in carbohydrates are at an increased risk for not meeting the AI for fiber, which could lead to adverse health outcomes. Funding Sources Funded by grants from the National Heart, Lung, and Blood Institute (HL073286) and the General Clinical Research Center, National Institutes of Health (RR-02635).