Stimulation of Diet-Induced Thermogenesis by Cold-Exposure

Overview

Human fat tissue is essentially white fat, the main function of which is to store excess energy intake, and to release it when necessary. Brown fat is far less abundant and is present in the body to burn fat (and thus energy) to generate heat to maintain body temperature around 96 degrees. This phenomenon is called thermogenesis. When humans are exposed to cold on a chronic basis, brown fat expands and becomes more active, and consequently burns more energy. The amount of brown fat is higher during winter, and daily short (20 minutes) exposures to cold might be sufficient to induce its activity. We hypothesized that daily short term (20 minutes) exposure to a cold environment (4 °C) for four weeks increases adaptive BAT-mediated thermogenesis. CIT and DIT will be increased proportionally (the increase in CIT and DIT will be correlated).

This study will have 3 phases: Phase 1: baseline testing. This phase takes place at the beginning of the study to establish several physical, physiological and metabolic studies and includes measures of height, weight, body composition, sedentary and resting metabolic rate in a metabolic chamber as well as your metabolic and cardiac responses to cold. Phase 2: cold exposure (treatment) phase. This phase is initiated immediately after phase 1 and will last 4 weeks. Each work day (Monday to Friday) subjects will have to spend 20 minutes in a cold room wearing light clothes. Phase 3: post-treatment testing. The same physiological and metabolic studies measured at baseline will be repeated over 3 days.

Conditions