Claim: Sleeping naked cools the body and promotes weight loss because the body produces more brown fat.
Category: Popular Beliefs
My Stake: Challenge claim (50 CRED)
Argument / Evidence:
- Sleeping without clothes necessarily means the body will be cooler.
- That sleeping temperatures reached when people sleep naked are low enough to “turn on” brown fat.
- Long term effects of cooler temperature on brown fat creation, and body weight.
The problem with this claim lies in the fact that they make a leap of logic by suggesting that sleeping naked and weight loss is directly related. The intermediating factor appears to be cold body temperatures, as demonstrated by studies that exposed participants to cold for short durations, resulting in ‘brown fat “turning on” and burning fat as a fuel source directly.
The proposed mechanism seems to be valid:
Mitochondria of brown fat contain a protein that enables them to generate heat by burning fats directly. Indeed, when the body is exposed to cold, brown fat consumes a significant quantity of energy already stored in its cells as lipid droplets. That is what makes this tissue so unique and critical in fighting the cold.”
Dr. André C. Carpentier, from Universite de Sherbrooke, and team set out to determine how humans might be able to switch on the brown fat so that it uses up fat. They found that exposure to cold temperatures seems to be the best trigger.
These studies were conducted by subjecting participants to temperatures of (18°C), which is considered an optimal temperature for sleep, so it’s feasible the human body could maintain 8-hours of exposure to these temperatures that can trigger brown fat to turn on:
The problem with this claim is that there is no evidence that demonstrates that sleeping without clothing necessarily means you will stay cooler. While it’s possible that the wrong choice of material can inhibit temperature regulation by trapping too much heat, this would be true whether that was bedding material or clothing material.
There is also a question, about the long-term effectiveness of cold-exposure on brown fat as a calorie burning mechanism: As, Dr. Carpentier said to CTV news:
While studies show a temperature which is considered ideal for sleeping adults (60-67 F, 15-19 C) can “turn on” brown fat, which may lead to weight loss, there is no causal relationship between sleeping naked and weight loss. It is also unknown whether or not the effect of cold-exposure on brown fat, and the potential for weight loss, would continue over prolonged periods of time.