Selective Reduction of Dietary Carbohydrate Versus Fat: Effects on Metabolism, Endocrine Physiology, Brain Activity and Reward Circuitry
试验速览
- 阶段
- 2 期
- 状态
- 已完成
- 入组人数
- 43
- 试验地点
- 1
- 主要终点
- Change in Respiratory Quotient (RQ)
研究概览
简要总结
Popular weight loss strategies often involve reducing an individual's consumption of carbohydrates or fat. However, no controlled study has been carried out to evaluate the effects of reducing carbohydrate versus fat consumption while keeping the other nutrients at standard levels to maintain an individual's weight. Researchers are interested in investigating how different restrictions of carbohydrates or fats affect the many processes involved in weight loss, including brain activity and blood and brain chemical composition.
详细描述
Popular weight loss strategies often prescribe a targeted reduction of dietary carbohydrate or fat. But surprisingly, no controlled human feeding study has ever investigated the effects of a selective reduction of dietary carbohydrate versus fat while keeping the other dietary macronutrients at their baseline weight-maintenance values. The present study was designed to address this knowledge gap and improve our understanding of how selective reduction of dietary fat versus carbohydrate may differentially impact the many feedback control processes that act to resist weight loss.
Objectives:
- To determine the comparative effects of two controlled fat- or carbohydrate-restricted diets and an outpatient weight loss program on blood and brain chemical composition, weight loss (fat and lean body mass), and regional brain activity in lean and obese individuals.
Eligibility:
- Healthy individuals between 18 and 45 years of age who are either lean (body mass index between 18.5 kg/m(2) and 25 kg/m(2)) or obese (body mass index above 30.0 kg/m(2), weight less than 350 pounds) and are right-handed.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 45 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- 未提供
排除标准
- 未提供
研究组 & 干预措施
Obese RF then RC
Obese adult volunteers (BMI above 30 kg/m2) randomized to receive an 85% reduction of baseline dietary fat (RF) for 2 weeks. After a washout period of 2 weeks, they then received a 60% reduction of baseline dietary carbohydrate (RC) for 2 weeks
干预措施: Reduced fat diet (Other)
Obese RF then RC
Obese adult volunteers (BMI above 30 kg/m2) randomized to receive an 85% reduction of baseline dietary fat (RF) for 2 weeks. After a washout period of 2 weeks, they then received a 60% reduction of baseline dietary carbohydrate (RC) for 2 weeks
干预措施: Reduced carbohydrate diet (Other)
Obese RF then RC
Obese adult volunteers (BMI above 30 kg/m2) randomized to receive an 85% reduction of baseline dietary fat (RF) for 2 weeks. After a washout period of 2 weeks, they then received a 60% reduction of baseline dietary carbohydrate (RC) for 2 weeks
干预措施: fMRI (Device)
Obese RF then RC
Obese adult volunteers (BMI above 30 kg/m2) randomized to receive an 85% reduction of baseline dietary fat (RF) for 2 weeks. After a washout period of 2 weeks, they then received a 60% reduction of baseline dietary carbohydrate (RC) for 2 weeks
干预措施: PET (Device)
Obese RC then RF
Obese adult volunteers (BMI above 30 kg/m2) randomized to receive a 60% reduction of baseline dietary carbohydrate (RC) for 2 weeks. After a washout period of 2 weeks, they then received an 85% reduction of baseline dietary fat (RF) for 2 weeks.
干预措施: Reduced fat diet (Other)
Obese RC then RF
Obese adult volunteers (BMI above 30 kg/m2) randomized to receive a 60% reduction of baseline dietary carbohydrate (RC) for 2 weeks. After a washout period of 2 weeks, they then received an 85% reduction of baseline dietary fat (RF) for 2 weeks.
干预措施: Reduced carbohydrate diet (Other)
Obese RC then RF
Obese adult volunteers (BMI above 30 kg/m2) randomized to receive a 60% reduction of baseline dietary carbohydrate (RC) for 2 weeks. After a washout period of 2 weeks, they then received an 85% reduction of baseline dietary fat (RF) for 2 weeks.
干预措施: fMRI (Device)
Obese RC then RF
Obese adult volunteers (BMI above 30 kg/m2) randomized to receive a 60% reduction of baseline dietary carbohydrate (RC) for 2 weeks. After a washout period of 2 weeks, they then received an 85% reduction of baseline dietary fat (RF) for 2 weeks.
干预措施: PET (Device)
Lean Control
Lean adult volunteers (BMI below 30kg/m2) placed on a weight-maintenance diet using a standard diet composition of 50% carbohydrate, 35% fat, and 15% protein on an out-patient basis
干预措施: fMRI (Device)
Lean Control
Lean adult volunteers (BMI below 30kg/m2) placed on a weight-maintenance diet using a standard diet composition of 50% carbohydrate, 35% fat, and 15% protein on an out-patient basis
干预措施: PET (Device)
结局指标
主要结局
Change in Respiratory Quotient (RQ)
时间窗: Baseline and day 14
Respiratory quotient was calculated as the ratio of carbon dioxide production to oxygen consumption as measured in a metabolic chamber for at least 23 continuous hours on days 2 and 5 of the baseline diet and days 1, 4, and 6 of the reduced-energy diets.
次要结局
- Change in 24 Hour Energy Expenditure(Baseline and 14 days)
- Caudate Dopamine D2-like Receptor Binding Potential (D2BP)(Day 2 of in-patient admission)
- Putamen Dopamine D2-like Receptor Binding Potential (D2BP)(Day 2 of in-patient admission)
- Change in Cumulative Fat Imbalance(Baseline and 14 days)
- Accumbens Dopamine D2-like Receptor Binding Potential (D2BP)(Day 2 of in-patient admission)