5. You Can Spot-Reduce Body Fat
This one is easy. No, you can’t. Spot reducing means targeting a particular body region for preferential fat removal, for example, doing crunches to rid your abdominals of extra fat. What you feel when you are doing crunches is muscle contraction and fatigue. The effort (energy expenditure) to create this is distributed across the body by increased heart rate, blood distribution and lung activity.6. You Should Do Low-to-Moderate Intensity Exercise to Burn Fat
Low-intensity exercise burns more fat than glucose (blood sugar) as a percentage of total energy, and high-intensity exercise burns more glucose than fat. Even so, the total energy expended for a given time period is more important, because you can still burn fat at high intensity, even though the percentage of the total may be lower.In addition, when you burn glucose doing high-intensity exercise, such as running fast or hard weight training, you empty your blood, liver and muscles of glucose, which then stimulates fat burning when you’re not exercising. You don’t have to exercise at a low-intensity to burn fat. Fat-burning “zones” were invented to sell treadmills and stationary cycles with electronic displays.
7. Low-Carb Diets Have a Metabolic Advantage
Just about all well-designed scientific studies on low-carb diets say that there is no such thing. Theoretically, diets with more protein should have a slight advantage, because protein makes you feel fuller, and it also takes a bit more energy to digest. This is a modest advantage, though, and likely to be insignificant in the long term, which is what 12-month comparison studies of low-carb diets have shown.Low-carb diets may indeed be more effective for some people in the short term, but it will be because they impose calorie restriction on the dieter rather than providing any special fat-burning advantage.
8. Eat Many Small Meals Rather Than Three Big Meals
Many small meals, as opposed to three main meals, is supposed to enhance weight loss by making you feel full for longer. In a technical sense, this is supposed to prevent blood glucose from dipping low in between meals, which may cause you to become hungry and overeat during the next main meal.Like many of the myths about fat loss, there is strong acceptance of this premise on many health and fitness sites. Weight trainers and body builders tend to be strong supporters of this idea. The problem is, there is no substantial evidence that it works. Even though a few early studies reported benefits, more recent evaluation has not found solid evidence to support this idea.
In fact, increased meal frequency may lower the “thermic effect of food,” which is the energy required to digest food. This would theoretically result in just the opposite of the outcome anticipated by the “small meal” supporters, showing a comparative increase in weight.
Even so, this idea is not as outlandish as some of the others, and more research may make the picture clearer. For now, though, you should not consider smaller, more frequent meals for weight loss as providing an advantage.
9. Weight Training is Superior to Cardio for Weight Loss
Generalizations such as these mean very little unless you measure the energy expenditure related to each activity. High-intensity activity will burn more energy than low-intensity activity during and also after exercise — the afterburn effect. High-intensity cardio would burn more calories than low- or moderate-intensity weight training. Actually, cardio generally burns more calories per unit of time, because the activity is constant, whereas weight training is intermittent, even though usually of higher intensity for short periods of time.The best strategy is to do both cardio and weight training.
10. You Can Burn More Fat Exercising on an Empty Stomach
You probably can burn a lot of fat this way because fat is a preferred fuel when blood glucose is low after you have not eaten for a while. You will then go home, though, and eat a large meal to refuel, and you will burn less fat, because glucose will be replenished in the blood and liver. Over the course of 24 hours, you will have periods of preferential fat and glucose burning for energy, in different proportions. It balances out.Blood glucose is low on an empty stomach when fasting -- first thing in the morning for example -- but you still need some glucose when you exercise. If you don’t eat before a workout session, you risk muscle protein being converted to glucose to maintain a critical level of blood glucose. It’s best not to do hard training on an empty stomach. A piece of toast or energy bar or fruit juice or sports drink is probably enough to give your blood glucose a little boost before you work out, which should prevent you using muscle for energy and still allow good workout energy expenditure.
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Bellisle F, McDevitt R, Prentice AM. Meal frequency and energy balance. Br J Nutr. 1997 Apr;77 Suppl 1:S57-70. Review.
Foster GD, Wyatt HR, Hill JO, et al. A randomized trial of a low-carbohydrate diet for obesity. N Engl J Med. 2003 May 22;348(21):2082-90.
Tai MM, Castillo P, Pi-Sunyer FX. Meal size and frequency: effect on the thermic effect of food. Am J Clin Nutr. 1991 Nov;54(5):783-7.
Taylor MA, Garrow JS. Compared with nibbling, neither gorging nor a morning fast affect short-term energy balance in obese patients in a chamber calorimeter. Int J Obes Relat Metab Disord. 2001 Apr;25(4):519-28.
