View all slides | Contents of this slide

Lecture Notes

Unfortunately we don't have complete control over everything that we saw on the previous slide relative to obesity. So we advocate a lifestyle approach to achieving and maintaining a healthy weight. What behaviors do you think are involved there? Of course if you guessed physical activity and energy intake you are correct! So, physical activity and energy intake, or your diet, are two behaviors that we focus in on when we're trying to manipulate lifestyle factors, or behavioral factors, for decreasing obesity.

And so, to start you might ask somebody to get baseline measures of how much they eat and how much they expend. So, very simply to get a sense for where they are on those, if you picture those scales that we saw a few slides back—are you in a negative energy balance, positive energy balance, or are you simply maintaining an equal energy intake and expenditure? In order to do this we might ask someone to complete food and physical activity logs for seven full days, and then look at what they did over those seven days. What did you eat? How many calories did you have per day? How many calories did you expend every day? And that can give a person a sense of whether they need to simply maintain what they've been doing or keep balancing the scale.

They also might need to unbalance the scale. So, maybe the person is in a positive energy balance where they're going to be gaining weight, even if they're not currently. If that's the case then we want them to unbalance the scale, right? We want them to either eat less or expend more through physical activity, or, ideally, do a combination of those two things.

And we'll note here that if you want to lose weight, one pound of fat is 3500 calories. So, ideally you use a combination of physical activity and caloric restriction to lose about a pound a week if your goal is to lose weight. And you do that by either reducing your caloric intake by about 500 calories per day or burning an extra 500 calories per day, or the third situation is, again the ideal, combining physical activity with caloric restriction. So you might increase your expenditure by 250 calories and decrease your intake by 250 calories, and then that gets you also in a balanced situation. So ideally we know that combining physical activity with caloric restriction works best, not only for losing the weight, but also maintaining your weight loss.