Exercising to lose weight - the jury's out

Weight loss is touted as one of the top benefits from exercise. But what if the correlation to exercise and weight loss were not as strong as was once thought?

If a person exercises, they are burning calories. If they consume less than they burn, the body transfers stored energy. This is a very simple way to look at it, but the process is much more dynamic than a lot of people understand. This is why exercise alone will not account to substantial weight loss.

Calories are the units used to measure how much energy is in food. It is a way to know how much fuel is being put in the tank. Different foods have vastly different calorie contents. The body has a base use that fuels the constant need to move blood, breathe, stay warm, and keep the brain active, etc. This is known as metabolism. Metabolism is not a fixed number, but responds differently based on a person's age, sex, body size, and how much they move.

Metabolism is affected by many variables. It was commonly thought that moving more results in a higher energy need. This is now being re-thought. The new theory is that if someone is moving more, metabolism strives to hold onto a given calorie need. The body will become thrifty, boosting its efficiency. It attempts to save calories by making the body uptake oxygen better, move more blood with less heart beats, slow down digestion while on the move. The body stores more ready-to-use fuel in the muscles. Conversely, the person who never moves or exercises will not have these adaptations.

Anthropologist Herman Pontzer recently discovered a person's metabolism and calorie expenditure aren't all that different from one another, despite such a vast differences in activity or body size. He spent time in Tanzania looking at the caloric expenditure of a hunter-gatherer tribe called the Hadza. Using novel techniques, he measured their calorie expenditure. His conclusion was calorie expenditure is nearly identical to that of modern Western society despite the tribespeople moving about all day, accounting for miles worth of activity.

They burnt about as many calories as a moderately active American.

This was then parlayed to folks back in the states. Research at looked at sedentary, active, and vigorously active individuals to compare. They found slight differences, but overall there was only around a 10 percent swing in how many calories per day the actives were using over the inactives. Ten percent of daily caloric expenditure isn't a lot if someone is desiring ample weight loss. About two-thirds of a pound per week. This is shocking, because a lot of obesity research overlooks this effect.

Interpreting these findings and turning it into actionable and practical advice is paramount. How should someone effectively lose weight? Is exercise not effective at all? What is the reason why lean people stay so lean?

Exercise should always be second-fiddle to diet for weight loss goals. This is simply because what someone isn't putting in their body is easier to manage than exercising the weight away. Making a few small changes to diet will have a much bigger impact.

When a person first begins to exercise, they will see a big effect on caloric expenditure. This is because the body is not yet adapted to moving more. Soon, the person becomes more fit, and they burn fewer calories per given exercise session. The effects fade. This shouldn't deter exercise because a body with more muscle will be using more calories. This body type can expect to be what is known as more metabolically active, especially in the recovery from exercise.

People stay lean because of habits, not necessarily because of metabolism. While genetics, body fat distribution, and chemistry all play a role, eating habits transcend all.

It's hard to overcome the siren call of all the good food just minutes away. This is a major cause of obesity. The availability and palatability of the foods lurking in the cupboards and taken out through the drive-through window are more calorie dense and available than the foods humans have eaten in previous generations.

Food is just too good, and too easy to get.

Once a person decides to eliminate some foods, and adopt a diet high in nutritious foods, calorie intake will fall and weight loss can be expected.

Diet is the key; other factors are secondary. Adopt behaviors which all point toward the goal desired. Diet, exercise, and daily movement all have their exclusive benefits, yet they synergistically work in concert to provide holistic health for the individual.