Now here’s a “Well, duh!” moment.
A recent study published in the New England Journal of Medicine looked at how obesity exacerbates age-related decline, and that “a combination of weight loss [from diet] and exercise provides greater improvement in physical function than either intervention alone.”
So, they found that physical ability from just dieting or just exercise doesn’t improve as much combining these two. Well, that’s brilliant.
Nevertheless, it gives me an opportunity to explain what exercise does, and what diet does for the human body.
First and foremost, exercise improves physical functioning. You get a training response where you become stronger, faster, more flexible, etc. Additionally, many studies have shown how exercise leads to a comprehensive improvement on other bodily functions such as the heart and lungs, but also the brain and the immune system. People who exercise regularly have better trained immunity for fighting disease. It also increases bone density.
Secondly, exercise improves our ability to make good food choices. For people with impulsive eating behaviours, looking for that junk food fix, exercise targets the same reward pathways in the brain that gives them a similar “fix” and helps reduce cravings. Exercise also decreases stress (which can lead to poor food choices and overeating), and increases health-specific willpower acting as a form of “gateway behaviour” to better eating.
Finally, exercise burns calories, but this isn’t as important as the first two, because an hour of hard exercise can be undone in ten minutes of gluttony.
On the diet side, eating nutritious food has a number of health benefits and can also fuel improved physical performance. Restricting calories causes weight loss, and a body not encumbered with excess fatty tissue can move more effectively.
For those looking to lose weight, my opinion is to focus on exercise first and forget diet for now, because too much change at once is exceedingly difficult and leads to relapse. Find an activity you like and get the exercise thing down first. Then when you’re ready, you’ll be better able to tackle the more challenging task of restricting calories.