The Right Exercise continued...
Of course, Jakicic's findings also support that other factor crucial for successful weight loss -- cutting calories.
The 200 women he evaluated, typically 5-foot-4 and weighing 192 pounds when his study began, all cut their calories to 1,200 to 1,500 a day and fat intake to no more than 30% of total calories consumed.
"In this study, they cut calories by almost one-third their previous levels," says I-Min Lee, MBBS, ScD, of Harvard Medical School, who wrote an accompanying editorial to Jakicic's study.
"It's a balance issue. You can exercise very little but eat nothing and still lose weight. It comes down to how much you are willing to sacrifice, in terms of what you eat and what you do to burn it off. Most people don't want to cut their food intake by too much."
Still, Lee tells WebMD that this study shows that a little exercise, done consistently, can do a lot of good.
Pump Up Your Fitness, Too
The researchers also found that all four levels of exercise had the same effect on improving fitness level. Looking at increases in oxygen consumption -- a measure of how well the body uses oxygen for energy -- the researchers found that all four groups had similar improvements after 12 months of exercise.
The Greatest Weight Loss
"You will get the greatest weight loss from changing your caloric intake in the short run," says Jakicic. "However, it appears that without the exercise, the initial weight loss is less and the long-term maintenance of weight loss becomes extremely difficult. So, diet without exercise will make the maintenance of weight loss very difficult."
Conversely, he says that exercise without dieting makes weight loss slow and probably less effective -- especially if you're looking to drop serious poundage.
His recommendation for the ideal combination: "If an individual reduces their current level of intake by 500 to 1,000 calories per day and exercises 30 to 60 minutes a day, the weight loss will be around two pounds per week, on average."