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Restricted energy intake affects nocturnal body temperature and sleep patterns
A Karklin1, H S Driver, R Buffenstein
1Department of Physiology, University of the Witwatersrand Medical School, Johannesburg, South Africa.
The American Journal of Clinical Nutrition
|February 1, 1994
Summary
Energy restriction in overweight women significantly lowered body temperature and altered sleep patterns. This suggests a hypometabolic state, impacting key physiological functions during dieting.
Area of Science:
- Endocrinology
- Sleep Science
- Human Physiology
Background:
- Energy restriction is a common weight management strategy.
- Understanding its physiological effects is crucial for health.
- Previous research has not fully elucidated impacts on thermoregulation and sleep.
Purpose of the Study:
- To investigate the effects of a 4-week energy restriction diet on nocturnal body temperature, sleep patterns, and blood variables in overweight premenopausal women.
- To determine if energy restriction induces a hypometabolic state.
Main Methods:
- Nine overweight premenopausal women underwent a 4-week diet of 3347 kJ/d.
- Nocturnal body temperature, sleep patterns, and plasma triiodothyronine (T3) were measured before and during the final 2 weeks of dieting.
- Data were collected 28 days apart to control for menstrual cycle variations.
Main Results:
- Participants lost 8% of their initial body mass.
- Plasma T3 levels significantly decreased (P < 0.05), indicating reduced metabolic rate.
- Minimum nocturnal rectal temperature significantly decreased (P < 0.05).
- Sleep onset latency increased, and slow-wave sleep decreased (P < 0.05).
Conclusions:
- Energy restriction leads to a hypometabolic state in overweight premenopausal women.
- This hypometabolic state is associated with reduced nocturnal body temperature and altered sleep architecture.
- Changes suggest decreased restorative and biosynthetic requirements during caloric deficit.