Originally Posted by Gibonius
I can't really take this argument seriously when you're trying to say that eating well is causative for activity. What possible evidence do you have to support this? A person who is fundamentally physically lazy, dislikes activity, has no appreciation or experience with sport, etc, is not suddenly going to start playing sports, running, and hitting the weight room simply because they have a spot on diet. If you're already inclined towards those activities, and have time, then sure you're going to be more apt to do them if your diet is good. Even then I'd say going from "good" to "excellent" wouldn't have much effect. But it's crazy to say that it's causative.
It's not as crazy as you may think. Research done by Dr. Robert Lustig, a pediatric endocrinologist, out of UCSF, showed that when he put obese children on an isocaloric, low-carb, fructose restricted diet, along with weight loss, something rather interesting would occur. What he found was that these children, who had previously no idea what exercise even was, were starting to become active. The parents were coming to him explaining how, after years of watching their children sit on the couch and playing video games all day, they were actually going outside and desired to be active. So, if before the restriction of fructose and refined carbohydrates these children had no desire to exercise or expend any energy whatsoever, and afterwards suddenly had the desire, what could be causing this? Did the children suddenly decide they wanted to be fit because they were now motivated to do so, or that they finally abandoned their lack of will-power? The causative factor in what is giving them the desire is the freeing up of energy, namely by a reduction of insulin, from a diet low in carbohydrate. By reducing insulin, they were no longer hoarding calories into fat tissue, but instead had access to it and were expending that energy in the form of exercise. This is just one example that diet does, in fact, affect the total energy expenditure of the individual. Just another point I'd like to make: It is essentially useless to exercise on a poor diet; you are simply creating a vicious cycle. Especially those trying to lose weight, exercise is not a very wise decision. By expending energy, you are simply making yourself hungry, and will be likely to overeat to compensate for this expenditure. The diet is what is causing people to be inactive in the first place by hoarding calories into fat tissue, thus making you overeat and conserve total energy. So, by keeping the diet the same, and trying to exercise, your body will have even less
available energy, and so you are more likely to overeat. I am speaking mostly of aerobic and cardiovascular activity.
Again let's be clear about what we mean by diet. You can have a diet that provides 100% of your requirements, and not be especially lean, if you're consuming too many calories. It is not "deficient" in anything, and the person's health is not going to suffer from the lack of leanness unless they push it too far and become seriously overweight or obese. There's no solid evidence that extremely lean people have better long term health (somewhat the opposite in fact), but there's substantial evidence that active people have much better health outcomes.
Activity increases muscle mass, increases bone mass and strength in aging people, improves mood, improves heart and lung function, etc. You need a good
diet to be able to work out effectively, but you can't get those things just by diet, even with a perfect diet. Obviously a perfect diet AND activity would be ideal.
are they active? I agree with, and acknowledge, all of the inherent health benefits of exercise, however by thinking that you can improve your health and reap the rewards of exercise alone, while ignoring your diet, is simply silly. By fixing the diet you will, in effect, be creating a much more active individual, who will then be able to prosper from all of the aforementioned benefits of exercise.