We have heard the admonitions to “Move More, Eat Less” from fitness gurus and other scoundrels. The implication is that if you are fat, it is your fault. “Get up off the couch, you lazy bastard.”
The problem with “Move More, Eat Less”: it is a lie.
It seems logical though, doesn’t it? After all, you rarely see fat marathon runners. But, as Gary Taubes has noted, you also rarely see short NBA players. And no one thinks playing basketball makes you taller.
What does science say? You might be surprised.
Dr. Briffa recounts a conversation after a lecture:
Over lunch, after my presentation, I was talking to the one of delegates who expressed doubt about my ‘opinion’ that aerobic exercise does not generally promote weight loss. On what basis? He told me that there are no overweight elite marathon runners. So, marathon running must lead to weight loss.
So commonly and strenuously have we had the idea that aerobic exercise drummed into our psyches, that perhaps it’s no surprise that this man held this opinion. However, the thinking here is obviously limited, and in more than one way.
In other words, I was asking him to consider that people don’t get thin because they are marathon runners, but are marathon runners because, at least in part, they are thin.
(Also, I did point out that my view on exercise and body weight is not really an ‘opinion’ – it’s actually based on quite overwhelming evidence in the scientific literature.)
This is not a new revelation. Exercise can bestow many benefits on the individual, including better overall health. It just won’t lead to weight loss. Science has known this for a long time.
Dr. Briffa points to a recent study looking at activity levels and obesity in children. If the study just looked at fat kids, and measured their activity level, it would show that they tend to be more sedate than their skinny counterparts. You would think that validates the belief that the active kids burn off more calories and are therefore thin. But this study is different; it looked at activity levels as the kids became obese.
The study followed 202 seven year olds in Plymouth, England for three years. They were drawn from 40 different schools, and 53% were boys. It was a good mix of children. There was no “intervention” in this study. They didn’t counsel them on nutrition, exercise, or anything else. Over the course of the study they measured their height and weight, and had them wear special activity meters for seven day periods.
Some segment of the population will gain weight over any three year period. Some of these kids did just that. And it is with these kids that the interesting facts come out. Comparing the physical activity to weight found there was no correlation between physical activity and weight gain. The kids who gained weight did not reduce their physical activity first. But there was something else found. After the kids gained weight, physical activity decreased.
That’s right: active kids got fat and then got less active. They didn’t get fat because they were less active.
As the study puts it:
Physical inactivity appears to be the result of fatness rather than its cause. This reverse causality may explain why attempts to tackle childhood obesity by promoting [physcial activity] have been largely unsuccessful.
For most people, especially obese people, exercise stimulates hunger. And what you eat is, in our opinion, more important than how much you eat. In a typical western person’s daily life, an increase in exercise often leads to increased food intake … and usually the worse food is used to “reward” the successful completion of good healthy exercise.
Part of the reason is simple math. So let’s say we decide to cycle for exercise. Instead of driving to Starbucks, we’ll ride our bicycle. And the Starbucks isn’t really that close! It will take us an hour to get there, as its over 4 miles away. We hop on our bicycle, and pedal four and a half miles to a Starbucks. We will expend approximately 260 calories. Great job!
We feel so good about ourselves, we order a Grande Caffe Mocha instead of our plain black coffee. It has 260 calories. Grab a muffin, a mint, or anything else, and if you accept the idea that calories matter, you are worse off than before.
What if we sat home and didn’t cycle? In that hour you would have expended 55 calories sitting on the couch knitting. Not exactly exercise, but if knitting keeps you from drinking that Grade Caffe Mocha, you are ahead of the game.
And that’s accepting the flawed idea of “calories in and calories out” used by so many of the same people that say “get off your fat arse and exercise”.
The truth is that we are more complex than machines. We don’t have gas tanks, and we don’t burn fuel. We digest food and metabolize it. In Loser, Biggest Loser we recounted Dr. Doug McGruff’s horror at seeing the TV show “The Biggest Loser” while on shift in his ER. The mistreatment of the contestants on the show, combined with the erroneous ideas promulgated by the sadistic “personal trainers”, is a prescription for failure.
Exercise conveys many benefits, but if you have to choose between adopting a better diet and exercise to lose weight, choose the diet. And the best diet we have found is the low carb diets, such as Protein Power, The New Atkins, or one of the other paleo diets now popular.