Higher Protein Intake During Energy Restriction Alters Dietary Patterns and Maintains Diet Quality

Abstract Objectives A higher protein diet can be a successful approach to weight loss and improved health outcomes. However, the effect of a higher protein diet on other foods in the diet is not known. Evidence suggests diet quality scores provide a comprehensive representation of dietary intake and the complex interconnected nature of nutrient intake. In this study, the objective was to examine the effect of protein intake during moderate weight loss using four diet quality scores in overweight and obese adults. Methods Overweight and obese adults (n = 235) were counseled, bimonthly, to reduce energy intake over 6 months following the ADA food lists. The diets were individualized so range of macronutrient intake varied, but all individuals were encouraged to consume > 0.8 g/kg protein. Dietary intake was assessed and validated at baseline and ≥ 6 days during the intervention. In addition to the Healthy Eating Index (HEI), the Alternative Healthy Eating Index (AHEI), Mediterranean Diet Quality Score (MDS), and Dietary Approaches to Stop Hypertension diet quality score (DASH) were adjusted for energy intake and used to calculate diet quality. Results Subjects (55 ± 11 years) were overweight and obese (BMI 28.9 ± 4.0 kg/m2) and consumed 17.5 ± 5.3% energy from protein at baseline. During the intervention, subjects lost 4.5 ± 5.4% body weight, with a 333 ± 605 kcal deficit and 18.7 ± 3.5% protein intake. During the intervention, only the HEI score correlated with protein intake (r = 0.240, P < 0.001); however, all scoring methods (HEI AHEI, MDS, DASH) showed consistent patterns of food groups changing with higher protein intake. As expected, there was greater intake of meat, but also intake of vegetables. In addition, diet quality scores that measured dairy (HEI, DASH, MDS), unsaturated fatty acids (AHEI, MDS) and sodium (HEI, AHEI) showed an increase with higher protein intake. Conclusions In individuals following a weight loss diet, higher protein intake consistently altered dietary patterns of low-protein food components including higher intake of vegetables, unsaturated fat, and sodium. In an overweight and obese population with no comorbidities, HEI, AHEI, MDS, and DASH diet scores are effective methods of measuring diet quality and food patterns during moderate weight loss. Funding Sources Financial support by North American Branch-ILSI and National Institute of Health-NIA is appreciated.