How you burn fat:
So you want to burn fat? Great!! Let’s follow the gurumantra – Calorie deficit! Let’s eat less than what is required to maintain our body weight at a constant level. And lo, the magic begins to unfold. Well, you start getting leaner, in almost any kind of diet with calorie deficit, maintaining the protein at a more or less optimum threshold (about 0.8 to 1 gm per pound lean mass) to make sure you don’t lose muscle mass. However, most people who already suffer with their health never really gave a thought about intake or protein, did they? 1 roti in the morning, salad for lunch, 1 apple for snack and 1 roti for dinner. Brilliant! 450 calories to shred you to the bone! (Sarcasm 101)
The “shredding” continues, and you are happily losing weight till you suddenly hit the rock hard wall where you can’t seem to lose any more weight, commonly known as hitting the “plateau”. So what do you do then?
Well, you decrease some more calories, and your membership in the lose-weight-club extends for some more time. Then, once again a plateau. You again go down some more. Well, this continues till the cat loses all its nine lives.. and eventually, you hit your final plateau! Then no matter what you do, you do not lose weight.
Lost pretty good amount of weight so far? That’s good. Now that you’ve achieved your weight loss goal (almost, perhaps), you go back to your normal routine (not necessarily eat a lot, maybe you just start eating at your normal maintainence calories) thinking that this achievement of yours will last you a lifetime.
Wish the world was that fair. What happens one year down the line? Well, you not only gain your lost weight back, but you end up getting fatter than when you started. People who have tried this kind of a traditional approach to dieting may be well aware of this experience as well.
The takeaway?? Your ‘lost’ weight doesn’t stay ‘lost’ forever!
Why? What went wrong? Eating at your maintenance should enable you to maintain your new weight after all. But why doesn’t it happen in almost 90% of the cases?
This riddle of the returning weight is precisely what this article aims at addressing. So let’s take the plunge!
The answer, as most of you might have already heard, is metabolic slowdown, or in extreme cases, metabolic damage or metabolic crashdown, whatever jargon you may wish to use. The thing to understand here is – it is a point where the metabolism is so suppressed that there’s no way to lose any more body fat, unless you starve. (Metabolic setpoint is a point where you can’t lose any more body fat. But if you decrease calories, you can still lose further weight. But in case of metabolic damage, you can’t go lower on any count – fat or weight. That’s the steel wall which you can’t move anymore.)
In such a scenario your basic mathematics of “calorie out – calorie in = weight lost” does NO justice, since the environment of the validity of this equation is no more the same. The machine’s state has shifted, your body doesn’t function the same way any more. Your metabolic rate goes down so low, that your body rearranges itself to make your body energy efficient, i.e., it produces more output than the energy it is supplied with (No, not really. The Calorie In Calorie isn’t violated, but your body compromises on its own functions). Result? No further weight loss. In fact you might start gaining weight at a calorie intake much lower than your on-paper maintenance calories!
What? Why? How? Puzzled? Read on…
Your metabolic rate is not a simple factor defined by a standalone mechanism. It is rather a coordinated, correlated, and unified collection of numerous biochemical processes that occur in your body. All these processes co-ordinate to signal the brain to adjust various systems of the body to increase their efficiency and give better output in return of the energy provided by downregulating the systems. Now we always knew that efficiency is a good thing right? Well, in case of metabolism, that’s a big NO. This would mean maintaining your body weight at lesser calories, and with subsequent decrease in calories while dieting down, or worse with several quick cycles of dieting down and bingeing up, thus hitting the point of metabolic damage.
Your body achieves this in the following way –
Reduction of total energy expenditure:
ATP is the energy currency of the body. A certain amount of energy is required for producing every unit of ATP energy in the mitochondria. Studies have shown that this required energy gradually goes down with a calorie restricted diet. The mitochondrial efficiency increases. Hence the age long calorie in and calorie out theory isn’t satisfied in this case. (http://www.ncbi.nlm.nih.gov/pmc/articles/pmc1413655)
Decrease in leptin
If your body is a car, and your fat stores are the amount of fuel in the car, then leptin is the fuel indicator that signals the brain about the current fuel reserves of the body. So what would decrease in leptin do? It would obviously signal the brain not to burn any more fuel. Worse, it may suggest the brain to add fuel. The next point is somewhat related.
Increase in ghrelin
Ghrelin is the hunger hormone. It makes you feel hungry. At a point of metabolic shutdown due to calorie restriction, ghrelin levels increase, thereby making it difficult to diet further and signals the body incessantly to fill in the energy reserves.
Thyroid hormone decreases
Thyroid levels are closely related to the metabolic rate of our body; higher the thyroid levels, faster will be our metabolism. When we eat at a deficit, the thyroid levels go down, thereby affecting the metabolic rate further and taking it further down (http://www.ncbi.nlm.nih.gov/pubmed/10837281 ; http://www.ncbi.nlm.nih.gov/pmc/articles/pmc2678563)
Repeated low calorie and post-diet binging cycles – Yo-Yo Diet
Worst case scenario is when you’ve dieted down and binged up many times. What this does is, it increases your fat to lean mass ratio. In simple terms, it makes you fatter than ever before. This decreases the basal metabolic rate (BMR) too. (http://www.ncbi.nlm.nih.gov/pubmed/19366882)
Thermogenesis drops down
Seems confusing? Well, I’ll tell you one simple thing. You think you are in the modern era where everything is available to you at the tips of your fingers. You command and it’s there. You don’t have to think about food. It’s abundant, and you’ll never run out of it. Well, at least you don’t have to hunt, or go for days without food. On the contrary, here’s a fun fact – you brain thinks exactly that. It still thinks that you’re the Neanderthal man who is vulnerable when it comes to food. Well mate, your body loves you. It will try to keep you alive no matter what it takes to do so. So even in shortage of food, it tries to function well, and becomes more efficient at utilizing the meagre amount of calories you provide it with.
Eating on a deficit, eventually results in lowered number of free testosterone available in the body.
- You heard that right. Your testosterone levels drop too on a hypocaloric diet followed for long. Testosterone is the magic hormone which can directly affect your ability to lose fat, or build muscles, apart from its primary function as a sex hormone.
- With lowered testosterone levels, your body compromises on its energy requirement and also its potential to maintain a proper body composition, thereby making you susceptible to muscle loss and fat gain.
Weight Regain and Factors affecting it –
So let’s get back to your story. Your metabolism goes down. Fine, but you do not know that yet. What you know is what is tangible, what you can see. And that is, till now you’ve been able to lose a good amount of fat and are happy with the results. So what do you do next? You celebrate and binge for some days, and after that you’re back on your maintenance calories (well, you gotta maintain the new weight right?) Weeks pass, you’re okay, Months go by, you’re still okay. But suddenly after 6-7 months you realize that you are fatter than when you started dieting. That’s when you decide to diet down again. Well, that is the recipe for double disaster for you. Why? Let me explain
First let me explain the factors that pave the way for weight regain –
Our favourite hormone leptin is secreted by the adipocytes and the total leptin amount accounts for the total energy reserve of the body, and with decrease in weight (fat mass), leptin levels also go down. You already knew that. What’s new, right? Well, interestingly what happens (and you can say your body hates you) is that the proportion of the decrease in leptin levels exceeds the actual decrease in fat mass. Now that’s your body kind of cheating, since your fuel tank indicator shows a greater decrease in fuel that what is actually used up. This will significantly hinder your subsequent weight loss endeavors, but all that your body is trying to do is to keep you alive, by setting up the environment against starvation, and also for subsequent increased weight regain when food is available.
Your satiety hormones (the reason you feel full) peptide YY3-36(PYY) and cholecystokinin decrease after weight loss, thereby making you more hungry thereby leading to hyperphagia (eating excessively). (http://www.ncbi.nlm.nih.gov/pubmed/22029981 , http://www.ncbi.nlm.nih.gov/articles/pmc2678563)
The biggest factor is yet to come. Read on –
Increase in number of adipocytes
It has been shown by studies, and extensively researched by a noteworthy researcher by the name of Maclean, that the number of adipocytes increases with subsequent refeeding after a calorie restricted diet. Now what does that translate into? Well, Even after you gain all that weight back, there’s still room for even more fat gain because of the newly added fat cells! (http://www.ncbi.nlm.nih.gov/pmc/articles/pmc2964201). This probably plays the biggest role in taking your fat mass (or weight, whatever you want to call it) from what you started with before your diet down, to beyond that, when you come back to the pavilion.
Phew!!! Now the million dollar question that comes from every disillusioned dieter – If dieting makes conditions this disastrous, then why diet at all???
Well, this is not the end. There are ways to prevent metabolic damage and the subsequent hyper-weight-gain. Your body is a beautiful machine. It adapts to whatever is thrown at it. It has a feedback loop for everything. It comes back stronger no matter how hard the fight. When you diet down, it buttresses itself by lowering the metabolic rate and maintaining itself at those low calories and keeps your body from starving. But when you diet up, It cannot adapt itself that quickly to your increased calorie intake. There is always an energy gap.
Studies have shown that the time required to close the energy gap after a calorie restricted diet is almost equal to the diet down time frame, meaning, to get your metabolism back to normal, you need exactly the time you dieted down for in the first place. Suppose your metabolism was at 1900 Kcal when you started and went down till 1200 in 8 weeks. Now to take your metabolism from 1200 to 1900 you’ll need around 8 weeks’ time. (http://www.ncbi.nlm.nih.gov/pubmed/2613424)
So what do you need to do to avoid getting fatter after a diet?
The answer is simple – Increase your metabolism/metabolic capacity. And that doesn’t happen in a day. All the factors that have been shown above and a dozen more that haven’t been mentioned, take time to upregulate and come back to normal. Mitochondrial efficiency, hormonal functions, insulin, leptin, satiety hormones, thyroid, and a host of other factors, and restriction of the growth of the number of new adipocytes.
And now, the part you’ve all been waiting for after all this rant about dieting down:
How to improve your metabolism/metabolic capacity?
In just three simple words – It takes Time.
So be patient, plan smart, and work hard.
- Ditch long hours of low intensity steady state cardio: Low intensity cardio has been shown to further reduce metabolic rate. It’s not that it will kill you, but it won’t make you stronger either. 20 minute cardio 3 times a week is maybe okay, but running on the treadmill and sweating on the elliptical for 2 hours everyday is definitely gonna take your metabolism down to rock bottom.
Instead, opt for High Intensity Interval Cardio. Studies have shown that six 30-second sprints burn more calories in the long run than a one hour steady state cardio, without reducing metabolism.
- Do not make the mistake of further dieting down by lowering your calories and promoting starvation after you hit your final wall. This will further deteriorate your metabolism and it will be extremely difficult to recover from such a situation.
- Reverse Dieting: The Ultimate Solution: The only solution to get your metabolism up and to recover from a metabolic shutdown is reverse dieting, at least based on anecdotal evidence. When you diet down, go as slow as possible, and after you hit the wall, or if you’re already starting at a high deficit, then do not rush up. Up your calories slowly but steadily, as slow as you can, thereby allowing your body the time it needs to upregulate its internal systems to adapt to the calorie intake. If the addition is systematic and slow, the body adapts to it pretty well. I’m talking in terms of addition of about 50-75 calories per week. This might seem to take long, but it will take a metabolically damaged individual from an almost anorexic condition to a metabolically much better condition, thereby bypassing the side effects of a calorie-restricted diet.When you are at it, put in periodic refeeds as well. Although remember, that it’s not a random binging spree, it’s a planned temporary calorie bump, after which you return to your base and continue with your reverse dieting strategy. Refeeds – in the short term, reverse dieting – In the long term.
- Build Lean Mass: Such a simple advice, but needs so much patience! Building lean mass is probably the one thing that can do wonders for your overall health and your metabolism. The muscle is an active tissue – What does that mean? It means that the muscle tissues need energy to merely even exist. That can significantly improve your condition when it comes to building up your metabolism, strength, and improving health markers. If you can build even 500-1000 gm muscle in a month, consider yourself lucky. And that doesn’t come easy. You need to work really very hard in the weights section of the gym and your diet needs to be precisely on point to make sure that you don’t put on fat when trying to build muscle.
Patience is the key here. Work hard and be patient!
When your body is given enough time to recover from the low metabolism by providing slow and periodic increase in calories, it adjusts bit by bit to the relatively new environment, which does not contrast drastically from its immediate earlier stage, thus paving the way for a healthy metabolic recovery. Moving back up this slowly may prove to be even more tough than actually dieting down because of the various factors at play – Ghrelin, satiety factors, etc. – thereby making you more hungry when increasing your calories and dieting up. But the end result is a healthy metabolism. So it’s worth it. This is why we suggest reverse dieting in our approach towards dieting as well. However, while anecdotal reports of successful reverse dieting have made reverse dieting very popular among the educated fitness community, research is needed to evaluate its efficacy, but as it has been highly successful, this is our best bet to reverse the effects of a calorie-restricted diet as of now. Hopefully future researches will prove the mechanism of its efficacy thereby unveiling the secrets of its success.
Dev Biswas, Nutrition Consultant, SQUATS
Editor-in-Chief, FITMAG magazine