Day 17 – The Gender Gap part II

“Gluttony is an emotional escape, a sign something is eating us.”

~Peter De Vries

218.8 lbs.

Losing weight is a simple numbers game, At its core it comes down to one formula:

Calories consumed – Calories expended = X

If X is greater than zero, your body will store the extra energy as fat, and over time you’ll gain weight. If X is less than zero, your body will consume some of your fat stores to make up the difference and over time you’ll lose weight. You can change X by changing either side of the equation. Eat less, and that’s fewer calories consumed. Exercise, and that’s more calories expended. See? It’s not rocket surgery.

Unfortunately most of us who actively try to lose weight do one or the other, not both. As someone who is now on day 17 of a starvation diet, and down almost 22 lbs from his starting weight, I can say first hand that eating less uses up fat stores (and, if you use the stupid method of extreme caloric reduction that I’m using, you also lose muscle, stored glycogen reserves, etc.). But will just doing more exercise burn off body fat too?

Yes, in theory. But in the real world the answer is usually no.

“In general, exercise by itself is pretty useless for weight loss,” says Eric Ravussin, a professor at the Pennington Biomedical Research Center in Baton Rouge, La., and an expert on weight loss.

Here’s why: exercise is more than just using energy to move. It has effects on your metabolism, appetite, and body composition. That last part is good news; as you work out and build muscle, your body needs to feed that new muscle so you burn more calories all day long, not just during your workouts. But the changes to metabolism and appetite depend on who you are. Or should I say what you are. All political correctness aside, research shows that men and women respond to exercise in different ways. More on that later.

When researchers at the Pennington center had volunteers change X to below zero by either cutting their calorie intakes by 25% or increasing their daily exercise by 12.5% and cutting their calories by 12.5%, everyone involved lost weight (each lost about 1lb a week). But in the exercising group, the workout was nearly an hour a day of moderate-intensity activity… “a lot more than what many people would be able or willing to do,” according to Ravussin.

Here comes the kicker: as exercise activity increased, so did appetites. Small changes in X can produce quick changes in certain hormones associated with appetite, like acylated ghrelin, which increases the desire for food, as well as insulin & leptin, hormones that affect how the body burns fuel.

Barry Braun points out “The body aims for homeostasis”. Thanks Barry. Who the hell are you? Associate professor of kinesiology at the University of Massachusetts at Amherst, in the American College of Sports Medicine? Oh.

Okay, so working out makes people hungry. No big surprise there… except I did mention a difference between men and women when it comes to exercise, and – surprise! – it’s appetite.

A study by our friend Barry, published last year by The American Journal of Physiology, had 18 overweight men and women walk on treadmills. Sometimes they’d eat enough to replace the calories burned that day, other times they wouldn’t. The men displayed little or no changes in their energy-regulating hormones or their appetites. But the women all had higher blood concentrations of acylated ghrelin and lower concentrations of insulin on the days they ate less than they had burned. Their bodies were directing them to replace the lost calories.

In physiological terms, Braun says, the results “are consistent with the paradigm that mechanisms to maintain body fat are more effective in women”. In other words women’s bodies, driven “by a biological need to maintain energy stores for reproduction,” fight hard to hold on to every ounce of fat.

So… exercise is pointless then, yeah? Well, no. Exercise, for men and women, is a great way to maintain a higher metabolism, a stronger immune system, and general overall health. It also helps people maintain their weight over time, according to a Harvard University study published in The Journal of the American Medical Association last month. In it, 34,000 women were tracked for 13 years starting at about age 54. Most put on 6 lbs or so, something we consider normal with getting older. But those who went for a brisk walk on a regular basis didn’t put on as much flab, or none at all.

“When you look at the results in the National Weight Control Registry,” – Braun getting in another 2 cents worth – “you see over and over that exercise is one constant among people who’ve maintained their weight loss.”

At the end of the day don’t join a gym, expect to get thin quickly, then reward yourself after every treadmill jog with beer and nachos. But as I’ve preached in this blog before, you’re more than numbers on a scale. A combination of diet and exercise will keep your fat down and your health up.

Votre santé!