A question from Jamie Meeks: In the last newsletter you said: 'Losing weight through exercise alone is really inefficient and requires loads of training. Training at 65% of your Maximum Heart Rate means that the majority of the fuel you are burning is fat but you are burning so little fuel that you need to spend hours at that intensity to do any good. The next thing is that it is not the stored fat around your middle that you are burning but dietary fat. So if you can only train 4 times a week you are better off training at a much higher intensity, say 85% of MHR.'You state that only dietary fat is being burnt as opposed to the fat around the waistline. Why is this and what is the difference in dietary and stored fat? Is this related to the training intensity or the fact that the individual is not 'dieting'? Surely the increased calorie expenditure above a state of normal (i.e. no exercise) would equal stored fat to be burnt as fuel, although there would be less fat reduction than if reducing food intake as well.Terry O'Neill: The difference between dietary fat and stored fat is whether the fat is still in the digestive system or concealed somewhere about your person. Dietary fat is the more readily available fuel. When you exercise, depending on the intensity, the fuel will be carbohydrates for high intensity and a mixture of carbohydrates and fat at low intensity. The maximum percentage of fat in energy consumption is 60%. Fat recently ingested and in the digestive system is easier to metabolise than fat that has been stored around the body. As a rule of thumb, dietary fat will supply around 40 minutes of low intensity exercise and it is for this reason that using exercise alone is a very inefficient way to lose weight. If you train for one hour you have only been working with stored fat for around twenty minutes. Fat provides twice the calories of fuel than carbohydrates, 9kcal/gram to 4.3kcal/gram. In twenty minutes, therefore, you will only burn a couple of grams of fat.The advantages of a higher intensity regime are that the rate of burning calories is far higher, and even if the percentage of fat in the fuel is lower, you will burn more calories. Secondly, you get the added advantage of overrun. What this means is that the higher intensity work has hoisted up the metabolism which stays up for some time after the exercise has stopped and continues to burn off the calories. If the calories you consume are less than the calories you burn then you will lose weight. As I have explained, fat is a high-energy fuel packed with calories and what's more, easily stored about the body. Carbohydrates on the other hand can only be stored in limited quantities, about 450 grams in the muscles and 150 grams in the liver, anymore than this in the diet passes straight through.You say you have put on weight. This means you are taking on board more calories than you are consuming. Yes, if you go from doing nothing to doing something you will burn more calories but all this may do is reduce the rate at which you put on fat. As men get older their body fat increases naturally and this is another factor in the equation. Time to bite the bullet Jamie old son, do what I told you or buy a new wardrobe.