Friday, August 7, 2009

Diets, exercise, and purposeful eating

I think I've suspected something like this for a long time. But now there's evidence:
The conventional wisdom that exercise is essential for shedding pounds is actually fairly new. As recently as the 1960s, doctors routinely advised against rigorous exercise, particularly for older adults who could injure themselves. Today doctors encourage even their oldest patients to exercise, which is sound advice for many reasons: People who regularly exercise are at significantly lower risk for all manner of diseases - those of the heart in particular. They less often develop cancer, diabetes and many other illnesses. But the past few years of obesity research show that the role of exercise in weight loss has been wildly overstated.
"In general, for weight loss, exercise is pretty useless," says Eric Ravussin, chair in diabetes and metabolism at Louisiana State University and a prominent exercise researcher. Many recent studies have found that exercise isn't as important in helping people lose weight as you hear so regularly in gym advertisements or on shows like The Biggest Loser - or, for that matter, from magazines like this one.
The basic problem is that while it's true that exercise burns calories and that you must burn calories to lose weight, exercise has another effect: it can stimulate hunger. That causes us to eat more, which in turn can negate the weight-loss benefits we just accrued. Exercise, in other words, isn't necessarily helping us lose weight. It may even be making it harder.
Earlier this year, the peer-reviewed journal PLoS ONE - PLoS is the nonprofit Public Library of Science - published a remarkable study supervised by a colleague of Ravussin's, Dr. Timothy Church, who holds the rather grand title of chair in health wisdom at LSU. Church's team randomly assigned into four groups 464 overweight women who didn't regularly exercise. Women in three of the groups were asked to work out with a personal trainer for 72 min., 136 min., and 194 min. per week, respectively, for six months. Women in the fourth cluster, the control group, were told to maintain their usual physical-activity routines. All the women were asked not to change their dietary habits and to fill out monthly medical-symptom questionnaires.
The findings were surprising. On average, the women in all the groups, even the control group, lost weight, but the women who exercised - sweating it out with a trainer several days a week for six months - did not lose significantly more weight than the control subjects did. (The control-group women may have lost weight because they were filling out those regular health forms, which may have prompted them to consume fewer doughnuts.) Some of the women in each of the four groups actually gained weight, some more than 10 lb. each.
What's going on here? Church calls it compensation, but you and I might know it as the lip-licking anticipation of perfectly salted, golden-brown French fries after a hard trip to the gym. Whether because exercise made them hungry or because they wanted to reward themselves (or both), most of the women who exercised ate more than they did before they started the experiment. Or they compensated in another way, by moving around a lot less than usual after they got home. [...]
You might think half a muffin over an entire day wouldn't matter much, particularly if you exercise regularly. After all, doesn't exercise turn fat to muscle, and doesn't muscle process excess calories more efficiently than fat does?
Yes, although the muscle-fat relationship is often misunderstood. According to calculations published in the journal Obesity Research by a Columbia University team in 2001, a pound of muscle burns approximately six calories a day in a resting body, compared with the two calories that a pound of fat burns. Which means that after you work out hard enough to convert, say, 10 lb. of fat to muscle - a major achievement - you would be able to eat only an extra 40 calories per day, about the amount in a teaspoon of butter, before beginning to gain weight. Good luck with that.
If you are at all interested in the diet/exercise/weight loss topic, do go and read the whole article; the various studies done and what they showed are extremely revealing and interesting.

Things like this can be frustrating to read, especially for those of us who have a few pounds to lose. What's the answer, though, if exercise doesn't really help? Is weight loss really all but impossible, as some think?

It's a lot harder than many people think that it is, but it's not impossible to lose some weight. But we have to define the terms "lose" and "some."

If by "lose" we mean reduce the numbers on the scale and maintain that newer, smaller number, then weight loss is very, very hard. And if by "some" we mean more than 5% to 10% of our current body weight, then weight loss is even harder. The people who never need to lose even 5% of their body weight, or who never see the numbers on the scale go up in the first place, sometimes erroneously assume that being fat means one is lazy, undisciplined, and a glutton. None of those is necessarily true--but the process necessary to lose a significant amount of weight and then keep it off is much more complicated than some people think it is.

Should we keep exercising? Of course--the health benefits of exercise transcend weight loss, and so long as the kind of "overcompensating" talked about in the article doesn't take over one's diet, exercise at least won't be an enemy to weight loss. But to lose weight, it's the calories that matter; you must create a 3500 calorie deficit, or burn 3500 more calories than you consume, for every pound you lose.

And one of our worst enemies in this battle is the modern idea of portion sizes; click here to take two short portion size quizzes.

The more I progress in my various attempts to lose weight and keep it off, the more I'm thinking that the key to this achievement is to create an approach to food that I think of as "purposeful eating." Just as "mindless eating" describes the quick trip through a fast-food restaurant's drive-thru and the resulting high-calorie, high-salt meal we don't really want, but are too hungry to resist, so does "purposeful eating" describe an attitude toward food that considers portion size and caloric content, that seeks healthy food and avoids the snack pitfalls, that looks for nutritional content over ease and convenience, and that manages to do the job of giving us energy and fuel without overdoing it to the extent that weight loss is halted or weight gain results.

I'm not sure how "purposeful eating" will work as a weight loss strategy, but I'll report back here when I've been doing it for a while. And I'm not going to give up on exercise--but I'm not going to expect the numbers on the scale to drop without a concerted effort on the calorie-reduction side of the weight loss equation.


Anonymous said...

I like what you say -- I think we should think of it also in religious, spiritual, devotional terms, treating our food as a gift to be enjoyed and savored, used as means to another end, not an end in itself or a bad end.

I'm working on eating as a sort of spiritual discipline right now, and it's doing good things for me, only one of which, I think, is weight loss.


Amy said...

I don't know if you've looked into various options for diets (and I use diets in the sense of lifelong eating habits, not temporary pound-shedding devices), but the NO-S DIET seems - to me - to be the most sensible approach and really tackles the problems of overeating and/or eating the wrong things (hint: the "no S's" stand for no seconds, no sweets, no snacking).

After I have my son, it's what I'm doing. No counting points or carbs or calories.

Rebecca said...

Aim for low carbs, not low calories...purposeful is great but be purposeful in the right direction. I had to actually count the carbs at first because I didn't know what foods had what amount of carbs, but after a few weeks I had a good sense of it and didn't have to count strictly. Overdoing carbs is often what causes overeating because the carbs (especially the carbs stripped of other components) trick your body into thinking you're hungry for more carbs.

CM said...

In grad school, I decided it didn't really matter too much what I ate...and I gained 30 pounds. I strongly believe in exercise as a part of overall fitness, but I will say that I have not been able to get myself into a regular workout routine. I have lost about 25 of those 30 pounds (over about 3 1/2 years), and most of it has been through portion control, and making sure more of my calories were nutritional calories (fruits and vegetable, whole grains, that kind of thing).

Charlotte (Matilda) said...

This study seems flawed to me. They draw the conclusion that exercise makes you gain weight because people were inclined to eat more after they exercised? I don’t follow that logic.

They told the participants not to change their dietary habits, but all four groups DID, even the control group. Who wants to actually have to admit to themselves and total strangers that they ate 4 donuts? They chose not to eat those things that would be embarrassing to write down. BTW, keeping a food journal is the first piece of advice given to compulsive/emotional over-eaters to hold them accountable for what they actually eat instead of allowing them to fool themselves and believe they only eat 500 calories a day.

Hunger is both a physiological sensation and a psychological one. How many of the participants claimed to feel hungry after exercising because psychologically, they thought they should?

Wouldn’t a more scientific study have recorded the dietary habits or caloric intake of each individual in each group and then insisted that each person maintained that (no more, no less) throughout the study to determine the effect of exercise alone on weight loss?

I could better accept a study that proved that exercise alone wasn't an effective means of maintaining motivation for losing weight for some people, for example... those who hate any kind of physical exertion so much that they believe they should reward themselves for doing it or those who can't stand even the smallest pangs of hunger and who can't offer those sensations (real or imagined) up as a sacrifice for someone else or for their weight loss efforts.

Deirdre Mundy said...

Purposeful eating hint-- look at nutritional content and make sure that whatever you eat also provides for a NEED.....

Also, analyze your cravings. (I do this all the time when i'm pregnant...)

For instance, I've found that when I have an uncontrollable craving for icecream, a glass of whole milk works just as well. (Must be craving the dairy fat? Who knows?) Except, it's a lot easier to stop at one serving of milk than one serving of Breyers Cookies and Cream!

Of course, sometimes I give now, when I can't stop thinking about Mushmelon (Like a giant, sweet cantelope) -- Obviously, my body wants the vitamins C, A and Fiber. But It's pretty hard to overeat when you're dealing with fruits and veggies!

Also, aim for nutritionally dense meals--Beef,Broccoli and Brown Rice, for instance. You'll feel full sooner and have longer between food cravings!

I've also found that Cheddar Cheese is a good craving/hunger killer.....

Not that I'm trying to diet while pregnant--- but if I don't eat mindfully, i'm constantly STARVING because my body won't leave me alone until it gets the nutrition it craves! So if I eat junk, I eat constantly.... It's not just calories... it;s about feeding your body so that it doesn't WANT more calories. (If you eat 1000 calories of chips and your body REALLY wanted protein and vitamins, you'll still be hungry--it's how we're wired!)

Anonymous said...

This is very interesting.
I like the purposeful eating and also, knowing yourself a little better helps too.
The more muscle mass you have, the heavier you will be BUT you also will burn more calories too.
I was hungry when I would take aerobics 3 times a week. Adding a small pasta salad before I went to work out helped a lot. But I was working on toning, not weight loss. I think now if I would add walking and other activities, I would loose weight (which I need to).
Also, keeping a food journal is a good idea especially to get a snap shot of your eating habits.

freddy said...

I agree with Charlotte, here. This study does seem to slant toward the results. The media being what it is, there are folks who will look at this and say, "See I don't have to exercise to lose weight! In fact, exercise will make me *gain* weight!"

I really like the idea of purposeful eating, and it's a good help to remember that there is no "one size fits all" diet and exercise program. It's very tempting to think that following *this* diet or *that* exercise program will take off the pounds and keep them off, and they may help, but we have to remember that everyone has a different metabolism and different capabilities. Better to learn about food, nutrition, growth and development and apply that knowledge over time to create the best diet for you.

Anonymous said...

I'm 42 and weigh less now than I did five years ago. I have four children and the youngest is 7. Basically, what we did that made the most difference in our life (and my weight) has been getting a dog. Just taking Fido out for a brisk walk (30 minutes, 4 to 5 days per week) has helped me shed 10 pounds and keep it off over the past 5 years.

Another thing, I don't snack at all. I eat breakfast (2 eggs, 1 slice toast) just about every day. I eat lunch and then nothing until dinner, and nothing after dessert.

Anonymous said...

Muscle is heavier than fat - so if you exercise you may gain weight but lose fat. "Weight" isn't always the best measure of health/ progress. Bodybuilders are very fit and weigh a lot afterall. A better measure in that study would have been bioimpedence analysis to see changes in muscle mass and body fat.