Is Our Summer Body
Frozen In Winter’s Icy Embrace?
Chef Craig discusses the benefits of Cold Thermogenesis.
So, it’s the shortest day of the year. The height of winter in other words, and it’s a bit chilly out. Can we embrace the cold in order to improve blood glucose control and burn through our excess fat stores? Is excess fat primarily designed to be used to keep us warm through winter? Is winter (or generally being cold) the key piece of the metabolic puzzle?
Let me back up and tell you where this is coming from. I’m a creature of habit, my diet is pretty well set week to week, month to month. I also do some exercise on Monday, Wednesday and Sunday – usually the same volume and intensity each time. So when I started to see a noticeable (and pleasing) reduction in body fat ‘round the old love handle region I was intrigued. I wondered what the cause was, I hadn’t changed anything about my routine – very curious.
Next day I was having my usual cold shower that I’ve had every day since September last year and I was thinking, “Wow, it’s not even the shortest day yet and the water is freezing cold.”
Aha! Grab tablet, Google incoherent search term; “does clod burn calories”, Google advises politely that it’s searching instead for “does cold burn calories” and there it is, a trove of research on all things cold and it’s effects on the body. Cold Thermogenesis is the term, which translates as heat produced due to the body sensing the cold (strictly speaking it’s Non Shivering Thermogenesis as it doesn’t involve your shivering muscles).
As humans, we have 2 main types of fat. White Adipose Tissue which can be thought of as stored calories and Brown Adipose Tissue which is used as a functional furnace for burning calories when we are cold. Brown Fat is brown because its cells contain mitochondria which gives it a brown colour compared with regular fat cells. What brown fat does is really amazing. Instead of the mitochondria producing energy for the cell it instead cycles the energy with nowhere for it to go and this produces heat – kind of like revving the car when it’s not in drive. This study gives a complete explanation of this concept.
So just how much energy does Brown Fat burn? This study showed that the study subjects burned on average an extra 250 calories from having their skin temperature held at 18°C for 3 hours – done daily this equates to 1 kg of fat burned in one month. This is about the same level of cold as sitting in a cool room dressed in shorts and a t shirt, not exactly torturous.
The same study showed that being cold removed glucose and fat from the blood, presumably to be used as fuel to produce the heat required to keep the subjects warm. The amount of energy your brown fat produces increases the colder your skin gets, but I like the study mentioned because it shows a big effect for such little discomfort.
The fact that being cold increases energy expenditure and utilises fat and sugar from the blood is incredible. There appears to be no increase in hunger or feelings of tiredness reported when people are exposed to the cold. Compare that to the 2 main strategies people traditionally use to control their weight and overall health.
Eating LCHF means we can control our insulin levels, reduce blood sugar, reduce inflammation and a host of other great benefits. But if someone is trying to lose weight then they need to cut calories, otherwise known as dieting. Your body slows down when you diet in the long term, meaning your body budgets its energy output on the number of calories you consume. As the intake of food goes down, so does the output of energy – and your body thinks it’s doing you a favour. This is partly why people plateau. This in depth review shows the extent of dysfunction that happens to our metabolism with chronic low calorie dieting – I don’t think calling it catastrophic is overstating it.
Exercise is a great way to improve and maintain our health, there’s no doubting that. It does require time and effort to do however and sometimes life gets in the way or you might get injured or you might be unwell and unable to get a workout in. The other aspect of exercise is it increases your appetite which if you’re not careful, can undo the caloric deficit some people use exercise for – meaning it might not burn off any extra calories.
Whole-food eating and exercise are essential aspects of our lifestyle to promote good health and our body weight goals. But in some ways it could be argued that Cold Thermogenesis is an even better weight loss strategy than either dieting or exercise.
Cold Thermogenesis (CT) doesn’t increase appetite despite the increased energy output, in other words, this study shows that people burn extra calories without feeling any hungrier than normal. The other major benefit of CT is the way it targets fat deposits as it’s primary fuel source. It also uses free fatty acids as well as glucose in the blood so it lowers blood glucose and blood triglycerides. An excess of either of these fuels is associated with Diabetes, Heart Disease, Metabolic Syndrome etc.
Unlike dieting, protein is not used as a fuel for CT so there’s no concern of muscle loss which is important for everyone, not just bodybuilders. It also increases our metabolism during CT and doesn’t slow it afterwards the way low calorie dieting does.
I’ve spoken to a few people about this and the response has been lukewarm (ha). My wife HATES being cold, but who actually enjoys the 8th, 9th and 10th squat of a set? Or who enjoys using their willpower to battle past cravings? I think the way we view things gives them meaning.
For me, knowing that being a bit cold is stimulating my metabolism makes being cold have a purpose instead of it just being less comfortable than not being cold. The other comment I got was “doesn’t being cold make you sick, you know like winter flu?!”
There is evidence to support this as Rhinovirus reproduces at temperatures just below body heat, so a cold wet nose is a good breeding ground – this susceptibility applies to runners too especially on morning runs. This can be countered by placing a scarf round your nose, mouth and ears or taking a cold shower instead which targets certain body parts instead of all of your exposed skin. There’s also evidence that suggests cold temperatures on the body mildly stimulate the immune system making it better at defending from illness.
One last thing to consider is how easy and low cost this is to try out. There’s no gym membership, you don’t have to buy any equipment and it may even save on power bills if you opt to have cold showers or turn the heating on less.
There is a lot of research being done in this area and a focus on combating obesity is on the mind of the researchers. I can’t help thinking this is seriously low hanging fruit. Just think, any building or office that happens to be heated could possibly benefit its occupants by dropping it’s thermostat by a degree.
The other angle researchers are taking is they are trying to develop a drug which stimulates Brown Fat in the body in order to effectively create the fat loss pill. I’m sure it would make more money than the GDP of New Zealand but why pay for something your body can do on its own.