Best for fat loss: Diet or exercise?

A study suggests there is no difference in fat loss between those who diet and those who combine diet and exercise.

Fad diets focus on what foods to cut, fad exercise programs promise special fat burning effects from mere minutes of exercise. Health authorities recommend a combination of healthy eating and daily exercise for the best fat loss results. Who's right?

A study published in The Journal of clinical endocrinology and metabolism (2007, Jan 2) hypothesized that exercise and reducing calories combined may have a greater effect on fat loss compared to reducing calories alone. It turned out there was no difference.

Researchers at the Pennington Biomedical Research Center, Baton Rouge, LA (Redman LM, Heilbronn LK, Martin CK, Alfonso A, Smith SR, Ravussin E) followed study subjects over a six month period. One group reduced calories by 25%, while another reduced calories by 12.5% and burned off an equivalent 12.5% calories through exercise resulting in both groups having a total daily caloric deficit of 25% less than their daily caloric needs (about a 400 to 600 calorie deficit daily). Subjects in both groups lost the same amount of fat; Men lost 27% of their fat mass and woman lost 22% of their fat mass.

The study has both strengths and weaknesses. The strengths are that monitoring and measuring energy intake and expenditure, as well as total fat loss was more meticulous than many other studies that have investigated the same theory. Subjects underwent Xray, and oxygen consumption measurements to accurately asses body fat and energy use. Study subjects also had food prepared by the research centers "metabolic kitchen" to control food intake.

Perhaps one of the greatest strengths of the study was that the subjects had behavior modification counseling to help them identify poor health choices and how to feel motivated by making healthy choices. Researchers felt this strategy would be helpful in keeping study subjects motivated to maintain the study protocol over the six months they were enrolled.

One weakness in the study is the number of study subjects was low with only 12 subjects in each intervention group, resulting in not enough people studied to reflect the results expected for most of the population.

The study methods are very robust despite the low subject enrollment so the results are at minimum reliable enough to use for designing a larger similar study, and at maximum can let us say that for the most part either diet or exercise, or both, will result in fat loss so long as a daily energy deficit is realized.

The researchers suggest that diet and exercise combined is the best approach because of the cardiovascular benefits of exercise. In fact, the group that exercised had a significant increase in cardiovascular fitness, whereas the diet only group did not.

But wait, there's more..
Is a calorie a calorie?

Yes. No.
Let's go wide scope for a moment. The media and the greater diet and exercise industry often oversimplify the results of such studies. There is too much focus on fat loss only.

Fat loss is not the only reason to watch what we eat and exercise. In fact such a focus is myopic and feeds the compulsive unbalanced frenzy to lose fat as fast as possible.

We shouldn't pit diet and exercise against each other embracing the winner and ditching the loser (and this was not the intent of the study). We want our food to supply our needed nutrients and energy while tasting good, and we don't want to eat too much or too little.

Exercise is for stimulation of muscles, bones, heart lungs, etc., and for having fun with physical activity, and we don't want to do too much or too little.

With balance in mind, what is the value of a calorie?

In terms of fat loss, it doesn't matter whether your caloric deficit comes from diet, exercise, or both; as long as you have a caloric deficit you will lose fat.

It terms of gaining fat it doesn't matter if you take in too many calories from carrots or butter; the extra calories will be stored as fat.

Here's the balance part.

50 calories of strawberry jam is not a significant source of vitamins and minerals.

50 calories of broccoli or sweet red/ green peppers will supply more than double your vitamin C for the day plus provide other nutrients and fiber.

In this case, while the calories are the same, the nutrition delivered with those calories are not. This is usually overlooked when we focus on calories only.

Not all fat is created equally.

If most of your fat intake is from saturated fats such as butter and red meat, your risk of cardiovascular disease increases. If most of your fat intake is from nuts, grains, fish (salmon, tuna), and oils like olive oil, your risk of cardiovascular disease decreases.

A diet delivering all of it's calories from fat is not healthy. A diet with a balance of fat's, carbohydrates, and proteins is healthy. Same calories, different outcome.

So where energy is concerned one calorie will always be one calorie, but where delivering nutrients is concerned our choice of calorie sources is very important.

If you find your self asking "what is better for me to lose fat; diet or exercise?", the answer is both or either alone; but you may need to reevaluate the reasoning behind your question. Are you into fat loss at all costs? Fat loss is important but that doesn't mean it supersedes the benefits of getting enough vitamins and minerals, or being fit. While losing fat be sure to meet your daily nutrient needs. For most who are on a caloric deficit to lose fat, daily nutrient (vitamins + minerals) needs can be met with between 1500 (women) and 2000 (men) calories; but this is pushing the limit.

Go here to see if you're meeting your daily requirements

© 2007 Cris LaBossiere Rhino Fitness www.rhinofitness.ca