The Weight Optimization Revamping Lifestyle using the Dietary Guidelines (WORLD) Study: Sustained Weight Loss Over 12 Months.

OBJECTIVE: This study aimed to compare two energy-restricted, nutrient-dense diets at the upper or lower ends of the dietary fat recommendation range (lower fat [20% energy from fat] versus moderate fat [35%]) on weight loss using behavioral theory-based nutrition education. METHODS: A total of 101 premenopausal women with overweight or obesity were randomized to an energy-restricted lower-fat or moderate-fat diet for 1 year. Interventions included 28 behavioral theory-based nutrition education sessions plus weekly exercise sessions. RESULTS: Both treatment groups experienced weight loss (-5.0 kg for lower fat and -4.3 kg for moderate fat; P < 0.0001), but there was no difference in weight loss or fat intake between groups. Total and low-density lipoprotein cholesterol decreased (-3. 4 mg/dL and -3.8 mg/dL; P < 0.05), and high-density lipoprotein cholesterol increased (1.9 mg/dL; P < 0.05) in both groups at 12 months. Diet quality, assessed by the Healthy Eating Index, increased significantly at 4 months versus baseline (70.8 [0.9] vs. 77.8 [1.0]) and was maintained through 12 months. Higher Healthy Eating Index scores were associated with greater weight loss at 4 months (r = -0.2; P < 0.05). CONCLUSIONS: In the context of a well-resourced, free-living weight-loss intervention, total fat intake did not change; however, theory-based nutrition education underpinned by food-based recommendations resulted in caloric deficits, improvements in diet quality, and weight loss that was sustained for 1 year.

Complementary feeding and micronutrient status: a systematic review.

BACKGROUND: Proper nutrition during early life is critical for growth and development. OBJECTIVES: The aim was to describe systematic reviews conducted by the Nutrition Evidence Systematic Review team for the USDA and the Department of Health and Human Services Pregnancy and Birth to 24 Months Project to answer the following: What is the relation between 1) timing of introduction of complementary foods and beverages (CFBs) or 2) types and/or amounts of CFBs consumed and micronutrient status (iron, zinc, vitamin D, vitamin B-12, folate, and fatty acid status)? METHODS: A literature search identified articles from developed countries published from January 1980 to July 2016 that met the inclusion criteria. Data were extracted and risk of bias assessed. Evidence was qualitatively synthesized to develop a conclusion statement, and the strength of the evidence was graded. RESULTS: Nine articles addressed the timing of CFB introduction and 31 addressed types or amounts or both of CFBs. Moderate evidence suggests that introducing CFBs at age 4 mo instead of 6 mo offers no advantages or disadvantages in iron status among healthy full-term infants. Evidence is insufficient on the timing of CFB introduction and other micronutrient status outcomes. Strong evidence suggests that CFBs containing iron (e.g., meat, fortified cereal) help maintain adequate iron status or prevent deficiency in the first year among infants at risk of insufficient iron stores or low intake. Benefits for infants with sufficient iron stores (e.g., infant formula consumers) are less clear. Moderate evidence suggests that CFBs containing zinc (e.g., meat, fortified cereal) support zinc status in the first year and CFB fatty acid composition influences fatty acid status. Evidence is insufficient with regard to types and amounts of CFBs and vitamin D, vitamin B-12, and folate status, or the relation between lower-iron-containing CFBs and micronutrient status. CONCLUSIONS: Several conclusions on CFBs and micronutrient status were drawn from these systematic reviews, but more research that addresses specific gaps and limitations is needed.

Systematic review methods for the Pregnancy and Birth to 24 Months Project.

The USDA's Nutrition Evidence Systematic Review (NESR) team specializes in conducting systematic reviews (SRs) to inform federal nutrition policy and programs. The NESR's dedicated staff collaborate with leading scientists to answer important food- and nutrition-related public health questions by objectively reviewing, evaluating, and synthesizing research using state-of-the-art methodology. NESR uses a rigorous, protocol-driven methodology that is designed to minimize bias; to ensure availability of SRs that are relevant, timely, and high quality; and to ensure transparency and reproducibility of findings. This article describes the methods used by NESR to conduct a series of SRs on diet and health in infants, toddlers, and women who are pregnant as part of the Pregnancy and Birth to 24 Months Project.

Creating the Future of Evidence-Based Nutrition Recommendations: Case Studies from Lipid Research.

Strategic translational research is designed to address research gaps that answer specific guidance questions. It provides translational value with respect to nutrition guidance and regulatory and public policy. The relevance and the quality of evidence both matter in translational research. For example, design decisions regarding population, intervention, comparator, and outcome criteria affect whether or not high-quality studies are considered relevant to specific guidance questions and are therefore included as evidence within the context of systematic review frameworks used by authoritative food and health organizations. The process used in systematic reviews, developed by the USDA for its Nutrition Evidence Library, is described. An eating pattern and cardiovascular disease (CVD) evidence review is provided as an example, and factors that differentiated the studies considered relevant and included in that evidence base from those that were excluded are noted. Case studies on ω-3 (n-3) fatty acids (FAs) and industrial trans-FAs illustrate key factors vital to relevance and translational impact, including choice of a relevant population (e.g., healthy, at risk, or diseased subjects; general population or high-performance soldiers); dose and form of the intervention (e.g., food or supplement); use of relevant comparators (e.g., technically feasible and realistic); and measures for both exposure and outcomes (e.g., inflammatory markers or CVD endpoints). Specific recommendations are provided to help increase the impact of nutrition research on future dietary guidance, policy, and regulatory issues, particularly in the area of lipids.

RM-493, a melanocortin-4 receptor (MC4R) agonist, increases resting energy expenditure in obese individuals.

CONTEXT: Activation of the melanocortin-4 receptor (MC4R) with the synthetic agonist RM-493 decreases body weight and increases energy expenditure (EE) in nonhuman primates. The effects of MC4R agonists on EE in humans have not been examined to date. OBJECTIVE, DESIGN, AND SETTING: In a randomized, double-blind, placebo-controlled, crossover study, we examined the effects of the MC4R agonist RM-493 on resting energy expenditure (REE) in obese subjects in an inpatient setting. STUDY PARTICIPANTS AND METHODS: Twelve healthy adults (6 men and 6 women) with body mass index of 35.7 ± 2.9 kg/m(2) (mean ± SD) received RM-493 (1 mg/24 h) or placebo by continuous subcutaneous infusion over 72 hours, followed immediately by crossover to the alternate treatment. All subjects received a weight-maintenance diet (50% carbohydrate, 30% fat, and 20% protein) and performed 30 minutes of standardized exercise daily. Continuous EE was measured on the third treatment day in a room calorimeter, and REE in the fasting state was defined as the mean of 2 30-minute resting periods. RESULTS: RM-493 increased REE vs placebo by 6.4% (95% confidence interval, 0.68-13.02%), on average by 111 kcal/24 h (95% confidence interval, 15-207 kcal, P = .03). Total daily EE trended higher, whereas the thermic effect of a test meal and exercise EE did not differ significantly. The 23-hour nonexercise respiratory quotient was lower during RM-493 treatment (0.833 ± 0.021 vs 0.848 ± 0.022, P = .02). No adverse effect on heart rate or blood pressure was observed. CONCLUSIONS: Short-term administration of the MC4R agonist RM-493 increases REE and shifts substrate oxidation to fat in obese individuals.

Yo-yo dieting in African American women: weight cycling and health.

OBJECTIVE: Research on the effects of weight cycling on health is mixed, strife with inconsistent definitions and the exclusion of African Americans. This study examined weight cycling prevalence among African American women prior to enrolling in a weight management program. Associations of weight cycling with physical and psychological health were conducted. DESIGN: Cross-sectional analysis. SETTING: Community-based weight-management program. PARTICIPANTS: 167 overweight or obese treatment-seeking African American women. MAIN OUTCOME MEASURES: Weight cycling was examined in relation to physiological factors, including eating pathology, mood, self esteem, and physical health, specifically current weight, ideal weight, peak weight, and blood pressure. RESULTS: Weight cycling was prevalent (63%). Cyclers had higher current and peak weights (P<.01). Blood pressure did not differ between groups. Cyclers had higher drive for thinness, less body satisfaction, and less self-esteem for appearance (P<.05). CONCLUSION: African American women are at risk for weight cycling and it may be associated with greater weight and poorer measures of psychological health.

Associations between eating competence and cardiovascular disease biomarkers.

OBJECTIVE: Explore the relationship between eating competence (EC) and biomarkers of risk for cardiovascular disease (CVD). DESIGN: Secondary analysis of data collected for a larger, 2-way crossover clinical trial. SETTING: Outpatient clinical research center. PARTICIPANTS: Forty-eight hypercholesterolemic (LDL cholesterol > or = 110 mg/dL) men (n = 19) and women (n = 29) 21 to 70 years of age. MAIN OUTCOME MEASURES: Participant descriptives, cardiovascular disease biomarker levels, and eating competence (EC) determined by the ecSatter Inventory (ecSI). ANALYSIS: T tests for differences in eating competence between males and females, analysis of variance for differences in risk between those categorized as EC or not. Associations between EC and baseline biochemical measures, as well as participant characteristics and dietary intake, were assessed by Pearson correlation analyses. Logistic regression estimated relative risk of CVD risk factors from ecSI scores. RESULTS: Several significant associations were found between EC total and CVD risk factors. Eating competence was positively correlated with HDL-cholesterol, and inversely associated with systolic and diastolic blood pressure. High EC participants had significantly lower ratios of total cholesterol: HDL-cholesterol and triglycerides: HDL-cholesterol. Participants who were not eating competent were 5 times more likely to have LDL-cholesterol levels > or =130 mg/dL and 7 times more likely to have triglyceride levels > or =150 mg/dL. CONCLUSIONS AND IMPLICATIONS: Eating competence appears to be a cognitive, affective construct with physiological manifestations, making nutrition education to increase eating competence a medical nutrition therapy.

The diversity of health effects of individual trans fatty acid isomers.

There are multiple adverse effects of trans fatty acids (TFA) that are produced by partial hydrogenation (i.e., manufactured TFA), on CVD, blood lipids, inflammation, oxidative stress, endothelial health, body weight, insulin sensitivity, and cancer. It is not yet clear how specific TFA isomers vary in their biological activity and mechanisms of action. There is evidence of health benefits on some of the endpoints that have been studied for some animal TFA isomers, such as conjugated linoleic acid; however, these are not a major TFA source in the diet. Future research will bring clarity to our understanding of the biological effects of the individual TFA isomers. At this point, it is not possible to plan diets that emphasize individual TFA from animal sources at levels that would be expected to have significant health effects. Due to the multiple adverse effects of manufactured TFA, numerous agencies and governing bodies recommend limiting TFA in the diet and reducing TFA in the food supply. These initiatives and regulations, along with potential TFA alternatives, are presented herein.

Dietary omega-3 fatty acid intake and cardiovascular risk.

Dietary omega-3 fatty acids decrease the risk of cardiovascular disease (CVD). Both epidemiologic and interventional studies have demonstrated beneficial effects of omega-3 fatty acids on many CVD end points, including all CVD (defined as all coronary artery disease [CAD], fatal and nonfatal myocardial infarction [MI], and stroke combined), all CAD, fatal and nonfatal MI, stroke, sudden cardiac death, and all-cause mortality. Much of the evidence comes from studies with fish oil and fish; to a lesser extent, data relate to plant-derived omega-3 fatty acids. Cardioprotective benefits have been observed with daily consumption of as little as 25 to 57 g (approximately 1 to 2 oz) of fish high in omega-3 fatty acids, an intake equivalent to >or=1 fish meal weekly or even monthly, with greater intakes decreasing risk further in a dose-dependent manner, up to about 5 servings per week. Fish, including farm-raised fish and their wild counterparts, are the major dietary sources of the longer-chain omega-3 fatty acids. Sources of plant-derived omega-3 fatty acids include flaxseed, flaxseed oil, walnuts, canola oil, and soybean oil. Because of the remarkable cardioprotective effects of omega-3 fatty acids, consumption of food sources that provide omega-3 fatty acids--especially the longer-chain fatty acids (>or=20 carbons) from marine sources--should be increased in the diet to decrease CVD risk significantly.

n-3 fatty acid dietary recommendations and food sources to achieve essentiality and cardiovascular benefits.

Dietary recommendations have been made for n-3 fatty acids, including alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) to achieve nutrient adequacy and to prevent and treat cardiovascular disease. These recommendations are based on a large body of evidence from epidemiologic and controlled clinical studies. The n-3 fatty acid recommendation to achieve nutritional adequacy, defined as the amount necessary to prevent deficiency symptoms, is 0.6-1.2% of energy for ALA; up to 10% of this can be provided by EPA or DHA. To achieve recommended ALA intakes, food sources including flaxseed and flaxseed oil, walnuts and walnut oil, and canola oil are recommended. The evidence base supports a dietary recommendation of approximately 500 mg/d of EPA and DHA for cardiovascular disease risk reduction. For treatment of existing cardiovascular disease, 1 g/d is recommended. These recommendations have been embraced by many health agencies worldwide. A dietary strategy for achieving the 500-mg/d recommendation is to consume 2 fish meals per week (preferably fatty fish). Foods enriched with EPA and DHA or fish oil supplements are a suitable alternate to achieve recommended intakes and may be necessary to achieve intakes of 1 g/d.

Dietary stearic acid and risk of cardiovascular disease: intake, sources, digestion, and absorption.

Individual FA have diverse biological effects, some of which affect the risk of cardiovascular disease (CVD). In the context of food-based dietary guidance designed to reduce CVD risk, fat and FA recommendations focus on reducing saturated FA (SFA) and trans FA (TFA), and ensuring an adequate intake of unsaturated FA. Because stearic acid shares many physical properties with the other long-chain SFA but has different physiological effects, it is being evaluated as a substitute for TFA in food manufacturing. For stearic acid to become the primary replacement for TFA, it is essential that its physical properties and biological effects be well understood.