I couldn’t have written a more provocative and obvious title could I? I mean, this is right to the point. Many authors have covered it before, yet so many have got it wrong.
It’s January. The gym is packed with those determined to start afresh and “sweat off some of that fat” that’s been building over the last few years. You’ve become dough-boy dad and the kids are happily poking fun at the similarities between your belly and that of the Coca-cola santa… enough is enough you say! This is the year I will finally have the body I’ve been dreaming of! I’m going to lose the dad bod and be happy and comfortable in my physique.
Except 4 weeks in to your regular gym routine and you’re not seeing results. There was a dramatic loss of water weight in the first few weeks but your Apple watch tells you you’re burning close to 1500kcals a day on exercise and you’re not losing any weight now?! That body fat isn’t shifting! So what’s the point?!
Exercise won’t make you lose fat.
You heard. For years, we’ve applied the simple physics of calories in vs calories out to our lifestyles under the guise of “eat less, move more” to lose weight. While calorie deficit is LITERALLY THE ONLY WAY TO LOSE BODY FAT, exercise doesn’t create that deficit, DIET DOES.
We unfortunately have oversimplified our bodies without paying attention to the actual science. There’s a whole host of people out there proclaiming their diet is better than someone else’s, but there’s also a whole host of actual smart and sensible people, who are right, saying that diet doesn’t matter for losing weight, calories do. And they’re absolutely 100% right. So how can I say in the same breath that exercise, which by definition burns calories, doesn’t contribute to weight loss.
Enter the evolutionary anthropological studies of total daily energy expenditure and a great man called Herman Pontzer (author of “Burn”, which I highly recommend you read or listen to if you want to truly understand the real ins and outs including all the studies, on how this concept works). Most of us have heard of BMR, basal metabolic rate. This is the number of calories required for your body to simply stay alive, excluding all other activity. If we laid you in a bed for a day and made sure you did nothing other than breathe and stay alive, your BMR would tell us how many calories we’d need to supply you to keep you alive in that vegetative state. But obviously, as human beings, we tend to move around, complete daily tasks like walking, socialising, eating, working, driving, sitting, thinking. And all these tasks require calories as well. Total daily energy expenditure tells us how many calories we need to support our daily lives, not just how many are required to keep us alive. With me so far? Where we tend to fall down, is on the next step…
We assume that energy required to exercise is required IN ADDITION to our daily energy expenditure, and to a point, it is. But what we neglect to factor in is how clever the human body is. Through studies of animals, hunter gatherer tribes and westernised populations, what Pontzer demonstrated is that actually, we adapt.
Humans as a species are built to survive – and thrive! As a result, the body uses our daily energy expenditure as a kind of budget. When we up our activity levels, initially we might see a slight up-tune in how many calories we expend, but over time, this settles. The body reocgnises that we need to redistribute our calorie “spending” habits and rather than telling us to take more calories in, which in the “wild” hunter gatherer environment we’re evolved for, would mean we needed more food and more time finding it, more energy digesting it and more risk when we didn’t have food sources available, it instead decides which integral processes we can cut back from. These include reproduction and immunity. So instead of adding exercise calories to our daily expenditure, we actually just re-budget. And that’s not a bad thing. We’ve seen that when we spend too much of our energy budget on reproductive hormones and immune cells, we can actually cause problems with overactivity in these areas (again, read the book, way more info on how this manifests and works, it’s actual science), so managing our spending here using exercise is a great way of managing and preventing these conditions.
So to simplify the results of this work and what it means for us, if calorie deficit is the ONLY way we can lose body fat and exercise DOESN’T mean we burn extra calories to do this…
The only way we can lose body fat is by creating a calorie deficit in our diet.
Yep. Tackling what you’re putting in your mouth is the only way you’re going to see genuine results with fat loss. And that sounds heartbreaking because it’s hard.
Does this mean exercise is a complete waste of time then? Quite the opposite. Although exercise won’t directly help you to lose weight, science has shown time and time again that the positive mind-focusing effects of exercising will help you to stay focused on fat loss and can also help regulate and recalibrate the brain’s drive for food and certain cravings towards high calorie foods, those enabling you to stay disciplined when it comes to donut dodging.
And let’s not forget the million and one ways in which exercise is beneficial for health. You see, the reason we focus on diet AND exercise, is for HEALTH. Altering body composition is just a small part of the picture of health and while for a lot of people, losing a bit of weight might be helpful to improving their health, there’s a whole other bit of improving health we need to think about.
So while exercising isn’t something you should give up, it might help to keep you motivated if you remember what it’s really for; mental and physical benefits, but NOT fat loss. It can help you to improve the look of your body by building muscle and it can help improve your daily life by building strength and confidence, but it can’t make you lose fat. For that, you’re going to need to knuckle down and address your nutrition properly. Sorry.