Nutrition science and information is constantly changing. Although this article has good points, my opinions and research have developed and changed. If you want to get started eating right for you, check out this new post on nutrition for beginners.
Leptin. Heard that word before? Leptin is the answer to your questions. Dieting is so hard because leptin is involved. We love leptin…it does wonderful things, but when you diet, it becomes your worst enemy.
What Is Leptin?
Leptin is a hormone that plays a key role in energy expenditure and intake. Sounds pretty important huh. Well it is. Leptin is your satiety hormone. Meaning, it tells you when you have eaten enough. It also is kind enough to raise your metabolism, something all dieters are striving for!
Sounds Good To Me…
Yeah, but its a little more complicated than that. Leptin levels revolve around a couple of things. Your level of body fat is one. People with higher levels of body fat generally have higher levels of leptin. Leptin is secreted from fat cells, so there is a direct correlation (obese people actually produce a lot of leptin but their receptors have had enough of it and dont recognise it…hence not ever feeling full).
The second thing is calorie intake. When you try to lose fat and restrict your calorie intake, your body lowers leptin levels. Regardless of your body fat level, if you lower your energy intake, your leptin production will slow down. Lowering leptin means your metabolism will drop. Also means you are not going to be satisfied and feel full.
In an ideal environment for the body, leptin levels are normal and the brain gets the idea that you have eaten enough. It keeps your metabolism high, and your body is primed for fat burning. As soon as you start dieting, leptin plummets. After only a week of dieting they can drop by 50%. You can see how this will greatly affect your ambition to lose weight. Your metabolism drops and you are always hungry. Your body does not want to burn fat. To make it even worse, when your metabolism drops, a couple of other nasty hormones get involved that really want to help your body STORE fat, and increase your appetite. Bit of a catch 22 isn’t it, you want to lose weight so you restrict your calories, but you also want to keep your leptin high and metabolism firing. Tough gig.
How Do I Stop This Crazy Cycle?
Mmm looks good…so eat it!
Cheat. Eat some crap. Go on, do it. Your personal trainer might come at you with a stick but I have a very good explanation.
OK, so I mentioned above that leptin levels drop dramatically when you diet, causing all sorts of problems that you don’t want. Basically making it near impossible for you to lose the pounds. The good news is, this is reversed really really quickly. It takes less than a day for leptin to get back to normal levels. With a fair increase in calories, your body will increase your leptin levels, thus your metabolism will go up and appetite will be suppressed. Great I hear you say, but then I am eating more calories and will just reverse all the good work I already did. Well, not if you are strategic about it.
If you cheat on your diet once a week (when we know that leptin can be at its lowest after dieting), you give your leptin and your metabolism a boost, setting and priming your body up for fat loss once you resume your diet. You can eat what you want for a day, try not to binge…it’s just not a good habit. Up your energy intake that day, get your metabolism firing. When you go back to dieting, you will be in a much better state than if you had simply let your leptin levels and metabolism hit rock bottom. It’s almost impossible to lose weight at this stage.
The best thing to eat is stuff that is full of carbs. There is a relationship between leptin, carbs and insulin. There has been research suggesting that upping your energy intake alone won’t really help. If you stuff yourself full of protein and fats, it won’t raise your metabolism and up your leptin levels as effectively as carbs will. So on you cheat day, concentrate on carbs.
There is another thing you should take from this carb business. If you should have carbs on your ‘cheat’ day, because they help stimulate leptin levels, then maybe you should still try to get them in on your diet days….There are so many diets out there that focus on limiting your cards. Yes, they do have the most energy in them, but you need them, and they help your body get into a state ready for fat loss. They can slow down the drop in leptin that is inevitable when dieting. Don’t ignore carbs all together in your diet, they play a very important role.
So, why is dieting so hard? Leptin. This hormone is your tool to weight loss. Be strategic, not stupid.