After some comments left to me from people, either online or in person, I think a clarification of my last blog is in order.
In that blog, I talked about how Dr. Oz's exercise-for-weight-loss recommendations would not work very well for weight loss (and long-term weight maintenance in particular).
Some of you interpreted it as me saying that, if you can't do 2500 calories per week, then you might as well not work out at all. Some of you also interpreted 2500 calories as being over an hour of intense exercise every day.
First, the issue is not a black/white issue. It's not an issue of "if I can't do 2500 calories per week, then I'll gain all my weight back." Something is always better than nothing. Certainly, 30 minutes at 3 days per week is better than nothing. You will get tremendous health benefits from this amount of exercise, including lower blood pressure, lower blood sugar, and improved mood.
It's also possible to lose weight on this amount of exercise. However, it's only possible if you're strictly adhering to a low calorie diet. Such a small amount of exercise alone usually does not create a sufficient energy deficit to create noticeable weight loss. The reason is that our bodies do a really good job of compensating for small changes in our energy expenditure, to keep our weight constant.
Let me give you an example. Let's say I jog for 30 minutes, 3 days per week. For a 170 lb person, that's about 284 calories per exercise session. That's 852 calories per week. In a perfect world, assuming everything else remains constant, that's about 1 pound of weight loss per month. It's tough to notice 1 pound per month, and a lot of people wouldn't be satisfied with that rate of weight loss. Now, that's assuming that everything else remains constant. However, when it comes to small changes in our energy expenditure, like this, our bodies will often adjust to it. An 852 calorie per week deficit is 122 calories per day. Such a small deficit can easily be wiped out with an extra tablespoon of peanut butter per day...or a cookie...or laying around a bit more during the day. We will often make these adjustments without noticing it...we might eat a bit extra, or be a bit more sedentary. So the result is not even 1 pound of weight loss per month. Rather, your weight stays steady.
This is why a low-calorie diet is necessary to lose weight on this level of exercise. Otherwise, you simply do not have the energy deficit to create noticeable weight loss. In fact, you need to create a big enough deficit to jolt your body into losing weight. Small deficits are too easy for your body to compensate for.
This is also why I felt Dr. Oz is being misleading. It's a show about weight loss, and most people expect significant weight loss. Some people might give up exercise completely out of frustration, if they had the unrealistic expectation that they would lose significant weight from his recommendations. Now, if Dr. Oz said something like, "This level of exercise only helps you lose weight in combination with a low-calorie diet", then he wouldn't be so misleading.
Also, I need to clarify that the 2500 calorie per week recommendation is for long-term weight maintenance. It's actually easier to get by with less exercise when you're trying to lose weight. Why? Because most people cut back on their calories when they're trying to lose weight. In fact, most of the energy deficit comes from cutting back on calories...not from exercise....and that includes the 20/20 program. However, once people reach their goal weight, they tend to start to eat more. This means they have to increase their exercise to compensate, so that they can continue to maintain their weight.
The research is very clear that 2500 calories per week is the threshold for keeping your weight from creeping back on. In one study, people who did about 2300 calories per week maintained about 75% of their weight loss. People who did around 1500 calories per week (that's about 3 one-hour cardio sessions per week) gained about half of their weight loss back.
This is also clear from research on the National Weight Control Registry. This is a national database of people that have lost at least 30 lbs and kept it off for at least a year. The research shows that these people do about 2800 calories per week in physical activity.
Now, keep in mind we're talking physical activity here. Physical activity does not always mean sweating your butt off in the gym. It includes any recreational activity, including walking, hiking, biking, etc. 2500 calories per week does not mean you have to do all of it in the gym.
I also want to get to the idea that some of you had, that 2500 calories is over an hour of vigorous exercise every day. That's not the case. In my last blog, I said that 2500 calories per week is about 35-40 minutes of vigorous exercise, 5 days per week. If you do more days per week, you can do less per day.
Now, if you're the type to do moderate exercise (like brisk walking), then, yes, it's over an hour a day, if you're doing 5 days per week. If you're doing it daily, you can get by with less.
Also, you can get by with less if you're making up for it in other ways. For example, I don't do 2500 calories of formal exercise per week, but I'm also very active through out the day (despite having a desk job). I've worn a pedometer before, and my daily steps have hovered from 10,000 to 14,000. My total daily energy expenditure (measured using the Sensewear Armband) is around 3,300 calories per day...even on days I don't work out. And, no, I don't have a fast metabolism (my metabolism is actually 10% below what you would predict for my height and weight)....I'm just active throughout my entire day. I'm also very aware of my food intake and rarely overeat.
Some of you thought my last blog would discourage people from exercise....that it might cause them to give up when they learned how much 2500 per week is. However, there's a lot of ways you can get that 2500 calories in...it doesn't mean you're a slave to the gym.
Nevertheless, losing significant weight, and keeping it off, is a huge commitment, and I don't think people should be misled as to it being anything less. It's not just the exercise...it's the time commitment required to change your lifestyle....the time in preparing food, the time in getting enough sleep, the time in effectively dealing with stress. Dr. Dedomenico says in the 20/20 Intro that it's 10-15 hour per week, part-time job for the rest of your life. He doesn't sugar coat it, and he's right. It's not easy, and nobody should be led to think that it will be easy. His part-time job comment doesn't seem to discourage too many people, because people are still packing his intros, and this program continues to be filled with clients...clients that are losing almost 40 lbs on average. We're obviously doing something right.