You can lose weight through dieting. You can lose weight even faster if you diet and exercise at the same time. But you cannot expect to drop any weight through exercise alone. It’s just impossible to out-train a bad diet. Here’s the skinny: Let’s say your daily dinner consists of a large Papa John’s pizza and a can of coke. You would need to run in excess of a marathon in order to burn that much energy. In other words, just to avoid putting on weight, you would need to find around five hours a day for running and keep your fingers crossed your knees could sustain the wear and tear.
Another way of appreciating why diet is more important than exercise is to look at what happens if you do no exercise at all. It’s not really that difficult to imagine – based on the latest Ministry of Health statistics, over 80% of China’s population are in this position. But even for the 80%, weight gain is not inevitable – in fact, a significant proportion of the population will do no exercise and still not put on weight due to something called the basal metabolic rate (BMR) (http://en.wikipedia.org/wiki/Basal_metabolic_rate). The BMR is the amount of energy your body needs just to keep your vital organs functioning. And it’s a fairly significant amount – approximately 1,500 calories per day for an average person. Throw in a certain basic level of activity – walking to the car, taking a shower, picking up the phone to order a pizza, and the average calorie requirements per person are somewhere in the region of 2,000 to 2,500. Consume less than that on a regular basis and you can quite easily lose fat despite doing no exercise.
Does it matter what foods you eat? Well, of course it does. 2,000 calories from junk food is not the same as 2,000 calories from fresh organic vegetables. Failure to provide your body with the right nutrients can wreak havoc on your body’s metabolism and ultimately cause illness. Thus, fix your eating habits first, try paleo, clean eating and natural/unprocessed foods. Otherwise, your valiant exercise efforts may come to no avail.