Burn Fat in Your Sleep, Start Tonight
One simple intervention at home can improve your metabolism while you sleep, and the positive benefits don’t end there.
The quality of our sleep is declining, which is a disaster for our health. As we toss and turn our nights away, we conjure more symptoms that force us into a vicious circle of poor sleep, metabolic dysfunction and weight gain. But, there is a way we can help break out of this destructive cycle and create one that, rather than worsens dysfunction and disease, feeds back into health. The good news is, it’s simple, and you can start tonight.
“a single poor nights sleep makes people more insulin resistant — a mechanism behind metabolic and cardiovascular disease.”
The Vicious Circle
Scientists demonstrated a decade ago that a single poor nights sleep makes people more insulin resistant—a mechanism behind metabolic and cardiovascular disease. Since then, more robust research has been added to the pile confirming a restless night’s negative effect on our metabolism. But the cherry on top is that just one night tossing and turning sabotages your dietary efforts the very next day by gravitating you towards junk foods. This combination increases your chances of becoming overweight and obese, which carries with it more problems for sleep.
Sleep issues torment the obese twice as often as people with a ‘normal’ body mass index (BMI). In a Swedish sleep study, with 18,000+ participants, insomnia was strongly associated with weight gain, although causation is impossible to pinpoint.
Overweight and obese people have a lower core body temperature. This cooler body is, in part, due to the energy sparing mechanism of insulin resistance, which preserves fuel for storage versus burning it for energy or heat. Like rationing logs, when stranded in a blizzard. The afflicted feels colder, but it’s 2020, so the thermostat gets twisted, and the discomfort fades.
In developed nations, the average temperature in our houses has risen in recent years. The authors of the research ask a question in their title, Could increased time spent in a thermal comfort zone contribute to population increases in obesity? ‘Contribute’? Yes, in a word, and that was their conclusion. But making our environments warmer is a double-edged sword.
Being toasty minimises the need for our bodies to burn calories for warmth. It also reduces our capacity to do so with the formation of an energy-hungry fat called brown adipose tissue (BAT). The fewer calories we use for thermal purposes, the more we have for storage; which is the opposite of what many of us are trying to achieve!
One Simple Intervention
Matthew Walker, sleep scientist and author of Why We Sleep, tells us ‘your core temperature needs to drop two or three degrees Fahrenheit to initiate good sleep and then maintain deep sleep.’ This decline in temperature begins about two hours before bedtime, set by your body’s clock, and the sleep hormone melatonin.
“The chilly group burnt between 5% — 13% more energy over the day.”
The ambient room temperature is critical for quality sleep. If your bedroom is too warm, you’re sabotaging all the stages of sleep and therefore increasing your likelihood of insulin resistance and entering the vicious circle. Also, you are missing out on the opportunity to synthesise brown adipose tissue (BAT) which is a special type of fat found around our spine, upper back and neck. It uses lots of energy and produces heat. Avoid losing these benefits by creating the ideal climate which seems to be between 60 and 67°F (15.6 and 19.4°C).
Get yourself a little thermometer, and see what works for you. I like it at about 12°C, that way the air feels cool and fresh as I inhale. I like having a cool head but snuggle beneath a warm duvet; the research supports brain cooling for a more restful night’s sleep too.
If you still struggle to sleep, try having a warm bath or shower. A review of the research concluded that as little as ten minutes in warm water, 1–2 hours before bedtime, improved dropping off, staying asleep, and the quality of the Z’ds. In part, it has this effect because warm water has a cooling effect on the inner body. As mentioned, this is a part of your body’s approach to sleep. If you want a magic combination of things try this:
- Turn the thermostat down to 60 and 67°F (15.6 and 19.4°C).
- Add Epsom Salt to a warm bath (magnesium is relaxing).
- Read a novel by candlelight.
- Don’t look at any screens during your wind-down to sleep.
How much difference does temperature make to fat burning?
Two groups of people were studied for energy expenditure over twenty-four hours. They were permitted to wear their own choice of clothes, but their diet and activity level were standardised. The first group enjoyed a cosy 82°F (28°C), the second a chilly 68°F (20°C). The chilly group burnt between 5% — 13% more energy over the day. Interestingly, the chilly group used more bedding and wore more clothes than the cosy group highlighting the importance of ambient temperature.
As mammals, we have plenty of thermoregulation techniques, from merely changing the proximity to our partners, pushing the duvet to one side, curling up or extending our bodies, all affect our temperature. The brain controls those actions as well as the invisible ones involving chemical messengers and changes in circulation. Whatever the technique, it’s clear that temperature both inside and outside of the body is critical for quality sleep which is foundational for robust health.
Alterations in temperature affect our sleep which then affects our metabolism in a few different ways. These changes increase our likelihood of becoming overweight and obese. Being overweight makes sleep harder, and around we go, getting deeper into trouble with each rotation.
Bringing the temperature down in your bedroom is a simple intervention you can do tonight. Take it slow, if it’s too cold, you won’t sleep, defeating the object. So, try lowering a single degree for a few days and in a week or so you’ll find the sweet spot.