The Effects of a Calorie Restricted, Very Low Fat Plant-based Diet and Multi-component Exercise Program on Metabolic Health in Metabolically Abnormal Obese Adults
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 8
- 试验地点
- 1
- 主要终点
- Change in insulin sensitivity
研究概览
简要总结
The purpose of this study is to understand how weight loss by a very low fat plant-based diet with an exercise program affects metabolic and cardiovascular health in overweight adults at high risk for disease. Outcome measures will include assessment of insulin sensitivity, β-cell function, body fat distribution, skeletal muscle and adipose tissue biology, cardiovascular function, cardiorespiratory fitness, muscular strength, immune function, and the gut microbiome.
详细描述
Reduced energy intake and increased physical activity have profound effects on cardiometabolic health as assessed by insulin sensitivity, β-cell function, serum lipids, intra-abdominal fat mass, intrahepatic triglyceride content, and blood pressure, and is the cornerstone of treatment for people with obesity. However, the specific additional therapeutic effects of regular exercise in conjunction with diet-induced weight loss are not clear. In addition, the optimal dietary macronutrient composition needed to reduce cardiometabolic risk is not known. The use of a very low fat, plant-forward diet is becoming increasingly popular to treat people with obesity and is the only diet therapy that is reimbursed by Medicare in the treatment of people with coronary heart disease.
Participants will undergo nutritional counseling and have supervised exercise training 4 days per week plus unsupervised exercise sessions performed 2 days per week until 7-10% weight loss is achieved. Meals will be provided and food diaries will be kept during weight loss. Tests before and after the intervention will include muscular strength and aerobic fitness, cardiovascular assessments, glucose tolerance tests, hyperinsulinemic euglycemic clamp test for insulin sensitivity, muscle biopsies, body composition scans, blood tests, and urine and stool collections.
The overarching goal of this project is to conduct a comprehensive characterization of weight loss induced by using a PB diet with regular exercise in people with obesity, prediabetes and insulin resistance, followed by a comparison of the effects of this study with those from another study that is evaluating the effect of the same amount of weight loss induced by using a PB diet alone, without exercise. Specifically, we will evaluate changes in body composition, body fat distribution, cardiopulmonary function, muscle strength, the plasma proteome, insulin sensitivity, beta-cell function, systemic inflammation, muscle cellular metabolic pathways, and the gut microbiome to determine cellular, multiorgan, and whole-body effects of PB diet alone and PB diet plus exercise. Accordingly, this study will fill two important gaps in our knowledge that have considerable physiological and clinical significance; the data from this study will provide: 1) a better understanding of the effects of calorie restriction-induced weight loss plus exercise on a series of key outcome measures, and 2) the potential additional benefit of adding regular exercise to a plant-forward diet.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Other
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 55 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Age ≥18 and ≤55 years
- •BMI ≥30.0 and ≤50.0 kg/m²
- •HbA1c ≥5.7%, or fasting plasma glucose concentration ≥100 mg/dl, or 2-hr OGTT plasma glucose concentration ≥140 mg/dl
排除标准
- •Medical, surgical, or biological menopause
- •Previous bariatric surgery
- •Structured exercise >2 days/week for ≥35 minutes of intense exercise (e.g., jogging, activity that causes heavy breathing and sweating) or ≥150 min per week of structured exercise (e.g., brisk walking)
- •Unstable weight (>4% change during the last 2 months before entering the study)
- •Significant organ system dysfunction (e.g., diabetes requiring medications, severe pulmonary, kidney or cardiovascular disease)
- •Cancer or cancer that has been in remission for <5 years
- •Polycystic ovary syndrome
- •Major psychiatric illness
- •Conditions that render subject unable to complete all testing procedures (e.g., severe ambulatory impairments, limb amputations, or metal implants that interfere with imaging procedures; coagulation disorders)
- •Use of medications that are known to affect the study outcome measures (e.g., steroids, non-statin lipid lowering medications) or increase the risk of study procedures (e.g., anticoagulants) and that cannot be temporarily discontinued for this study
- •Use of antibiotics in last 60 days
- •Smoke cigarettes, use marijuana >2 x/week, or use of illegal drugs
- •Men who consume >21 units (e.g. glass of wine or bottle of beer) of alcohol per week and women who consume >14 units of alcohol per week
- •Pregnant or lactating women
- •Vegans, vegetarians, those with lactose intolerance and/or severe aversions/sensitivities to eggs, fish, nuts, wheat and soy, and/or any individuals with food allergies that induce an anaphylactic response
- •Persons who are not able to grant voluntary informed consent
- •Persons who are unable or unwilling to follow the study protocol or who, for any reason, the research team considers not an appropriate candidate for this study, including non-compliance with screening appointments or study visits
研究组 & 干预措施
Weight loss with diet with exercise
Persons with obesity with blood glucose concentrations higher than recommended and a moderate to high amount of fat in the liver (people with metabolically abnormal obesity) will be tested before and after ~7-10% weight loss. Following baseline testing, participants will be placed on a caloric-restricted plant-based very-low-fat (PB) diet and an exercise program until ~7-10% weight loss is achieved; they will then be re-tested so that pre- and post-intervention outcomes can be compared.
干预措施: Weight loss with very low fat plant-based diet and regular exercise (Other)
结局指标
主要结局
Change in insulin sensitivity
时间窗: An average of 4 months from baseline testing to 7-10% weight loss
Liver and skeletal muscle insulin sensitivity will be assessed by hyperinsulinemic euglycemic clamp technique, before and after weight loss.
次要结局
- Change in fat mass and fat free mass(An average of 4 months from baseline testing to 7-10% weight loss)
- Change in intra-hepatic triglyceride content(An average of 4 months from baseline testing to 7-10% weight loss)
- Change in 24 hour glucose concentrations with feeding(An average of 4 months from baseline testing to 7-10% weight loss)
- Change in 24 hour metabolite concentrations with feeding(An average of 4 months from baseline testing to 7-10% weight loss)
- Changes in gene expression in skeletal muscle tissue(An average of 4 months from baseline testing to 7-10% weight loss)
- Change in gut microbiome(An average of 4 months from baseline testing to 7-10% weight loss)
- Change in insulin clearance(An average of 4 months from baseline testing to 7-10% weight loss)
- Change in muscular strength(An average of 4 months from baseline testing to 7-10% weight loss)
- Change in fasting plasma glucose(An average of 4 months from baseline testing to 7-10% weight loss)
- Change in 24 hour hormone concentrations with feeding(An average of 4 months from baseline testing to 7-10% weight loss)
- Changes in body weight(An average of 4 months from baseline testing to 7-10% weight loss)
- Change in exosome-mediated intercellular signaling(An average of 4 months from baseline testing to 7-10% weight loss)
- Change in beta-cell function(An average of 4 months from baseline testing to 7-10% weight loss)
- Change in aerobic fitness(An average of 4 months from baseline testing to 7-10% weight loss)
- Change in glycosylated hemoglobin (HbA1c)(An average of 4 months from baseline testing to 7-10% weight loss)
- Change in markers of inflammation(An average of 4 months from baseline testing to 7-10% weight loss)
- Changes in body mass index(An average of 4 months from baseline testing to 7-10% weight loss)
- Change in plasma proteome(An average of 4 months from baseline testing to 7-10% weight loss)