Obesity experts would beg to disagree with the first lady, who said last month that it's the "small changes that add up" in fighting childhood obesity. Contrary to what Michelle Obama and many dieters believe, the body is actually wired to adapt to minor lifestyle changes—one less cookie a day, a few extra minutes of walking—to prevent these changes from making you lose weight. Small steps may prevent weight gain, but it takes big moves to take off pounds.
The imbalance between what obese children are eating and the calories they are burning is so big that putting a dent in it would require a change along the lines of walking 10 miles a day for 10 years—not drinking one less soda a day. What's more, a lot of regulation of food intake happens at the level of deeper drives, not of conscious decision-making. “If we just expect that inner-city child to exercise self-control and walk a little bit more, then I think we’re in for a big disappointment,” an obesity expert tells the New York Times.