Endocrine and Metabolic Responses to Exercise and Diets
Conditions
Keywords
exercise, high carbohydrate and high fat diets, insulin, gut peptides, appetite, metabolism, glucose
Brief summary
Determine whether the mid-day suppression of hunger and amplified increase in the release of glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide 1 (GLP-1) following morning exercise is due to increased fat content of the diet per se or a combination of high fat diet after morning exercise. The action of gut peptides, particularly GLP-1, on gastric emptying is likely to be important in mediating its effects on postprandial appetite and glycemia (Nauck et al. 1997). Our hypothesis is that exercise amplifies gut peptide secretion when diet is enriched with fat, and that this stimulus suppresses the hunger sensation.
Detailed description
Specific aim: Determine whether a change in macronutrient composition from 60% carbohydrate and 25% fat to 30% carbohydrate and 45% fat is responsible by itself for suppression of hunger and increased secretory response of glucose-dependent insulinotropic hormone (GIP) and glucagon-like peptide-1 (GLP-1), or whether these changes depend on preceding exercise. We will measure (a) concentrations of plasma GIP and GLP-1 by chemiluminescent multiplex assay, (b) concentrations of plasma ancetaminophen to assess the gastric emptying rate, (c) concentrations of plasma insulin, and glucagon by radioimmunoassay, and glucose, ketone bodies, and free fatty acids with appropriate spectrophotometric methods, (d) hourly appetite responses with visual analog scale under two conditions: sedentary (SED) and exercise (EX). Hypothesis: Hunger suppression and secretion of GIP and GLP-1 after the morning meal will be greater with slower gastric emptying rate when a meal consisting of 45% fat and 30% carbohydrate follows three hours after a 2-hour bout of moderate-intensity exercise than in the absence of exercise.
Interventions
OTHERExercise and diets
Exercise and high-fat diet Exercise and high-carbohydrate diet Sedentary and high-fat diet Sedentary and high-carbohydrate diet
Sponsors
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
University of Michigan
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
FEMALE
Age
50 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* Postmenopausal status * Age 50 to 65 years * BMI between 20 and 30 kg/m2. * Good health status (normotensive, fasting glucose \< 100 mg/dl, , hematocrit \> 32%, hemoglobin \>12 mg/dl) * Absence of restricted food intake * Absence of endocrine and metabolic disorders requiring medication other than hormonally corrected hypothyroidism * Absence of musculoskeletal disabilities that would prevent walking
Exclusion criteria
* Presence of endocrine and metabolic disease requiring medication, other than hormonally corrected hypothyroidism * Presence of musculoskeletal disabilities that would prevent walking * Smoking * Active dieting * Absence of listed inclusion criteria * Unwillingness to follow study protocol.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| daytime hourly appetite ratings | 36 hours | Changes in daytime hourly appetite ratings to two bouts of exercise followed by either a high-carbohydrate or a high-fat meal |
| Plasma concentration of beta-hydroxybutyrate | 36 hours | Changes in plasma concentration of beta-hydroxybutyrate to two bouts of exercise followed by either a high-carbohydrate or a high-fat meal |
| Plasma glucose concentration | 36 hours | Changes in plasma glucose concentration to two bouts of exercise followed by either a high-carbohydrate or a high-fat meal |
| Plasma insulin concentration | 36 hours | Change in plasma insulin to two bouts of exercise followed by a high-carbohydrate or a high fat diet |
| Plasma glucagon concentration | 36 hours | Changes in plasma glucagon concentration to two bouts of exercise followed by either a high-carbohydrate or a high-fat meal |
| Plasma concentration of glucose-dependent insulinotropic peptide (GIP) | 36 hours | Changes in plasma concentration of glucose-dependent insulinotropic peptide (GIP)to two bouts of exercise followed by either a high-carbohydrate or a high-fat meal |
| Plasma concentration of free fatty acids | 36 hours | Changes in plasma concentration of free fatty acidsto two bouts of exercise followed by either a high-carbohydrate or a high-fat meal |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Plasma concentrations of peptide tyrosine tyrosine (PYY) | 36 hours | Changes in plasma concentrations of peptide tyrosine tyrosine (PYY) to two bouts of exercise followed by either a high-carbohydrate or a high-fat meal |
| Plasma concentrations of glucagon-like peptide-1 (GLP-1) | 36 hours | Changes in plasma concentrations of glucagon-like peptide-1 (GLP-1)to two bouts of exercise followed by either a high-carbohydrate or a high-fat meal |
Countries
United States
Outcome results
None listed