Type and amount of dietary protein in the treatment of metabolic syndrome: a randomized controlled trial

Abstract

Background: Food-based dietary patterns emphasizing plant protein that were evaluated in the Dietary Approaches to Stop Hypertension (DASH) and OmniHeart trials are recommended for the treatment of metabolic syndrome (MetS). However, the contribution of plant protein to total protein in these diets is proportionally less than that of animal protein.Objective: This study compared 3 diets varying in type (animal compared with plant) and amount of protein on MetS criteria.Design: Sixty-two overweight adults with MetS consumed a healthy American diet for 2 wk before being randomly allocated to either a modified DASH diet rich in plant protein (18% protein, two-thirds plant sources, n = 9 males, 12 females), a modified DASH diet rich in animal protein (Beef in an Optimal Lean Diet: 18.4% protein, two-thirds animal sources, n = 9 males, 11 females), or a moderate-protein diet (Beef in an Optimal Lean Diet Plus Protein: 27% protein, two-thirds animal sources, n = 10 males, 11 females). Diets were compared across 3 phases of energy balance: 5 wk of controlled (all foods provided) weight maintenance (WM), 6 wk of controlled weight loss (minimum 500-kcal/d deficit) including exercise (WL), and 12 wk of prescribed, free-living weight loss (FL). The primary endpoint was change in MetS criteria.Results: All groups achieved ∼5% weight loss at the end of the WL phase and maintained it through FL, with no between-diet differences (WM compared with WL, FL, P < 0.0001; between diets, P = NS). All MetS criteria decreased independent of diet composition (main effect of phase, P < 0.01; between diets, P = NS). After WM, all groups had a MetS prevalence of 80–90% [healthy American diet (HAD) compared with WM, P = NS], which decreased to 50–60% after WL and was maintained through FL (HAD, WM vs WL, FL, P < 0.01).Conclusions: Weight loss was the primary modifier of MetS resolution in our study population regardless of protein source or amount. Our findings demonstrate that heart-healthy weight-loss dietary patterns that emphasize either animal or plant protein improve MetS criteria similarly. This study was registered at clinicaltrials.gov as NCT00937638.

Heart Disease and Stroke Statistics—2017 Update: A Report From the American Heart Association

“…The following factors have been reported as being inversely associated with incident metabolic syndrome, defined by 1 of the major definitions, in prospective or retrospective cohort studies: muscular strength, 179 increased PA or physical fitness, 134,180 aerobic training, 181 moderate alcohol intake, 86,100 fiber intake, 182 fruits and vegetables, 183 white fish intake, 184 Mediterranean diet, 185 dairy consumption 140 (particularly yogurt and low-fat dairy products 186 ), consumption of fermented milk with Lactobacillus plantarum , 187 animal or fat protein, 188 hot tea consumption (but not sugar-sweetened iced tea), 189 coffee consumption, 190 vitamin D intake, 191,192 intake of tree nuts, 193 avocado intake, 194 long-chain omega-3 polyunsaturated fatty acid, 195 potassium intake, 196 ability to interpret nutrition labels, 131 insulin sensitivity, 157 ratio of aspartate aminotransferase to ala-nine transaminase, 163 total testosterone, 153,157,197 serum 25-hydroxyvitamin D, 198 sex hormone–binding globulin, 153,157,197 and Δ5-desaturase activity. 199 In cross-sectional studies, increased standing, 200 a vegetarian diet, 201 subclinical hypothyroidism in males, 202 and marijuana use 203 were inversely associated with metabolic syndrome.…”

Higher protein intake is associated with increased risk for incident end-stage renal disease among blacks with diabetes in the Southern Community Cohort Study

“…This notion is supported by a meta-analysis showing that moderate protein intake improves blood pressure, a risk factor for CKD and ESRD [48], and by results from the Framingham Heart Study that showed protein intake is inversely associated with blood pressure [50]. In view of recent studies [32, 51] showing that regardless of the macronutrient targeted, various popular diets are equivalent in achieving weight loss, our results support avoidance of high protein intake when macronutrients are considered for weight loss in blacks. On the other hand, it is imperative to avoid excessive carbohydrate or solid fat intake in order to replace the limited protein intake in these patients, especially ones with diabetes mellitus.…”

“…Consumption of higher amounts of protein has historically been recommended in the setting of obesity and diabetes for weight control [32, 42] and is thought to be associated with favorable metabolic adaptations, including diet-induced thermogenesis, preservation of lean body mass and improved glycemic control by upregulation of hepatic gluconeogenesis [43, 44]. Despite these metabolic advantages, there remains concern that long term high protein consumption may contribute to the development of kidney disease.…”

“…Despite American Diabetes Association nutrition guidelines (15%-20% protein intake as percentage of total energy), high protein-low carbohydrate energy–restricted diets (30% protein and 40% carbohydrate) have emerged as an effective weight loss strategy in patients with diabetes [32, 33]. Limited literature exists on the effects of protein intake on kidney function in populations that have a high burden of risk factors for kidney disease, including black populations [11], and no study has examined whether racial differences in dietary protein intake contribute to differences in incidence of ESRD.…”

Testosterone a key factor in gender related metabolic syndrome

“…Macronutrients ingestion influence changes on blood substrates and hormones causing significant perturbation on insulin‐sensitive tissue, in particular, on muscle and adipose tissue . The reduction of the energy nutrition diet in patients with MetS caused a weight loss improving insulin resistance and cardiovascular risk markers , independently from the diet composition . In young women, weight loss improved insulin resistance significantly, and testosterone concentration dropped while SHBG increased with a consequent improvement of ovarian function , particularly in women with PCOS .…”