It’s well established that in order to lose body fat and/or body weight, you need to bring your daily calorie intake below your maintenance level for a certain time period. At first you lose weight, then your progress slows and then you hit a plateau where you seemingly can’t lose any more weight. If you reduce your calorie intake even further, now you start to lose muscle in addition to losing fat due to your insufficient calorie intake. Again, that’s not good because this will lower your metabolic rate, making it even harder to lose fat. Also, when you restrict your calorie intake for a period of time, your body starts to think that you’re starving and reacts by lowering your metabolic rate and increasing your appetite.
Researchers believe that the reason your body does this relates to levels of a hormone in your body called leptin. The role leptin can play in keeping you lean is yet another reason not to banish carbohydrates (carbs) from your diet, since occasionally overfeeding on carbs can revamp your leptin levels.
If you’re on a reduced calorie diet, leptin levels will begin to fall in your body. When leptin levels fall in the body, this effectively reduces your resting metabolic rate (RMR), triggers increased cortisol production (a catabolic hormone that promotes muscle loss and makes it hard to lose fat), and also increases your appetite, essentially promoting body fat gain. It is your body’s defence mechanism because it thinks you are starving. To keep your leptin levels normal and hence your appetite sated and your RMR at optimal levels, it is helpful to have occasional overfeeding days (particularly of carbs). This could be one day a week where you forget all about your diet and eat whatever you want in whatever quantities you want. Most likely you’re going to consume a lot of high carb foods, which will aid in increasing your leptin levels.
Try to make the majority of your overfeeding day comprised of carbs but avoid sugary foods such as fizzy pop, sodas, biscuits, and other sources of high fructose corn syrup. Also, try to go approximately 1000 calories higher than your maintenance calorie intake for the overfeeding day to assure a good response.
You could still lose a lb a week even with the overfeeding day. For example, if you stay at a 750-calorie per day deficit below your maintenance level during the other 6 days per week and you’re 1000 calories over your maintenance during the overfeeding day, that’s still a 3500-calorie deficit for the week (+1000 – 750×6 = -3500). Since the overfeeding is only one day per week, it will not ruin the benefits of the other 6 days per week where you’re following a good diet and will actually supercharge your metabolic rate to make sure you keep your fat loss/weight loss efforts on track. What you’re actually doing is tricking your body into thinking that food is plentiful once again and it doesn’t have to lower your metabolic rate since it no longer thinks it is starving.
Besides being important physiologically for maintaining continual fat and weight loss, the overfeeding day is also very important mentally by giving you that one day a week to look forward to where you can overeat and not worry about it.
NOTE that for a smaller individual with lower daily calorie requirements, you need to modify the calorie deficits and surpluses to smaller amounts.
Personally, my typical overfeeding day includes a large pizza and a cake! I may also have the occasional glass or two of red wine or even a couple of pints of beer. I look forward to my treat day as it gives me the opportunity to let my hair down (for those of you who know me, I have very little hair but you get my drift!!).
When you initially undertake a weight loss programme, I wouldn’t recommend the overfeeding day until you have reached at least your short-term goals. Otherwise, you just think it’s ok to eat pizza and drink wine a lot. Only incorporate the overfeeding day WHEN you feel ready.
Paul Edgar of Body and Mind Fitness Company
Personal Trainer to women over 25