Recently I got into a discussion about whether exercise is really necessary in a weight loss program. The other guy was saying . . . ‘well, if you just cut calorie intake you’re going to lose weight . . . if you starve you lose weight; witness concentration camps and so on’. And of course, Gary Taubes has been stirring up the diet and exercise community with his irreverent, but flawed views.
It’s a trite argument isn’t it? If you don’t eat, or eat very little, inevitably you will lose weight, fat and muscle. We all know that; except that’s not what we’re really talking about today. If you’re overweight you need to find a pattern of living that allows you to maintain a normal weight and eat well enough so that you enjoy life without having to do “diets”.
What I recommend is moderate calorie restriction in conjunction with a substantial increase in physical activity. And I’m not alone. Increasingly the science supports this, as do many successful weight losers.
The trouble with low-calorie diets by themselves is threefold:
- You reset your metabolism — downward. This is diet-induced thermogenesis. The body senses a low-calorie environment and decides to reduce its basal energy expenditure. It’s a survival mechanism that’s evolved over thousands of years.
- On low-calorie diets you lose not only muscle, but bone as well. Okay, when you stabilise your weight you may get some of this back, but it’s not ideal.
- Without exercise, you don’t get all those other proven benefits like protection from heart disease and some cancers, improved bone density, mental health, and perhaps protection from dementias as well as a list of other benefits.
Proven as a practical approach
Professional physical activity guidelines have for several years recommended that one needs to exercise an hour a day for most days of the week to lose weight and to keep it off. This has recently been confirmed by a study of women published in the Archives of Internal Medicine
Not only that, but the US National Weight Control Registry – a program that keeps track of successful weight losers — found that most of their successful listers did just that: exercised for about an hour a day in addition to their day-to-day activities. It doesn’t have to be all high-intensity stuff, because many did a lot of walking.
Low energy density, high-nutrient foods
One way to trick the body into maintaining metabolism while you reduce calorie intake is to eat plenty of low energy density foods — along with the increase in exercise. That means fruit and vegetables, salads, soups, bowl foods, beans, lean meat and not too much fat, refined carbohydrates and sugars. This is a proven approach called Volumetrics, which originated with Barbara Rolls at Pennsylvania State University.
Giving the body plenty of fibre, water and bulk to deal with even though the calorie count is comparatively low, tends to keep that metabolism from dropping too much.
Exercise – the fourth macronutrient
Food pyramids increasingly include physical activity in their recommendations because the best evidence suggests that uncoupling physical activity from food consumption creates a body environment that is not ideal for weight loss and maintenance, or health. This also reflects an evolutionary state built over tens of thousands of years when early humans moved much more than we do today.
I understand that some people can’t do much exercise. The infirm, injured and invalid have additional challenges, but the effort may be just as important for many people in this situation.