Why Can’t I Lose Weight? – HTLW 12

By Jason Fung, MD

Why can’t I lose weight? I hear this question all the time. It’s usually followed by something like “my best friend SkinnyBitch used this internet diet and lost 30 pounds. Why can’t I?” The basic question is something like this. If their friend uses a LCHF diet to lose weight, why doesn’t it work for me? Or, if somebody uses a Paleo diet, why doesn’t it work for me?

The answer really lies in the multi-factorial nature of obesity. Let’s go back to our Hormonal Obesity Theory (HOT) diagram.

If you don’t remember all the parts to the aetiology of obesity, you may want to review my 6 part lecture series on YouTube or review the last 45 or so blog posts about the aetiology of obesity. Start with Calories part 1.

As you can see, insulin is the main driver of obesity. But there are many things that can increase or decrease insulin. Refined grains, carbohydrates, and animal proteins can all increase insulin levels. Cortisol is also a major player in stimulating insulin secretion. Fructose increases insulin resistance directly which indirectly leads to increased insulin levels.

There are also factors that are not related to the ‘what we eat’ question. This is the key role played by insulin resistance. Insulin resistance both causes and is caused by high insulin levels – a classic vicious cycle. This accounts for the time-dependent nature of obesity. The fat get fatter. The longer you have obesity, the harder it is to get rid of it.

Why? Because the longer you go through the cycle of high insulin –> insulin resistance –> high insulin, the worse it gets. So long standing obesity is much harder to eradicate than recent obesity, as everybody already knew.

There are also a number of protective factors against obesity. The incretin effect, vinegar and fibre all help protect against the rise in insulin and play a protective role.

The key to understanding obesity is that many different things can contribute to the development and the treatment. Consider the analogy of your car not starting. There could be multiple problems. For example, the battery is dead, the car ran out of gas, or the spark plugs are worn out. So, if your problem is that the battery is dead, filling up with gas will not help. Neither will replacing the spark plugs. That seems kind of obvious.

But then, websites proliferate about how changing batteries is the cure for cars that don’t start. It is filled with testimonials of how people changed batteries and their cars effortlessly started. Other people attack the website saying that they changed batteries and nothing happened. Instead, they filled up with gas and the car started, so obviously, the key to starting the car is filling up on gas.

That’s exactly what happens in the sad sack, wacky world of weight loss. When you try to lose weight, people assume that there is only one problem for everybody. If your problem is insulin resistance, then reducing carbs may not be the best strategy (intermittent fasting may work better). If your problem is sleep deprivation/ stress, then increasing fibre is not going to be too good.

Cutting sugar works well for those people whose problem is excessive sugar intake. They write books and websites about how sugar is the devil. Others think that is ridiculous and think that refined grains (wheat) is the real devil since they’ve done well reducing grains. Others think that stress relief is the major problem in weight loss. Others blame calories. They all ridicule each other and fill the internet with testimonials. Worse, they all start bickering about how the real problem is carbs, or sugar, or wheat, or calories, or stress, or sleep deprivation, or fibre, or animal proteins etc.

You must understand that they can all be correct. Obesity is not a single problem. There is no single solution. A low sugar diet works amazingly for some, and not at all for others. Just as replacing the battery will work for some cars amazingly and not at all for others.

So – why can’t I lose weight?

Because you must be targeting the wrong pathway. You must find the particular problem that is causing your obesity and target that pathway.

Example 1– Let’s say that you suffer from a chronic pain syndrome, or fibromyalgia. This increases your stress level and your cortisol is chronically high. This leads to high glucose and insulin stimulation. This causes weight gain. Since cortisol is your problem, then you need to use treatments that target that pathway. This would include medical treatment for chronic pain, acupuncture, massage, meditation, yoga etc. This will help lower your cortisol level and treat your weight gain problems.

Reducing your carbohydrate or calorie intake will not be particularly successful. This is because these were not the problems increasing insulin levels in the first place.

Example 2 – Suppose that you are chronically sleep deprived. We know that this situation increases cortisol levels and will lead to weight gain. Lowering the sugars in your diet will not be particularly successful, because that was not your problem. You need to either find a new job, or improve your sleep hygiene or just plain get more sleep.

Example 3 – Suppose that your main problem is the insulin resistance cycle. This vicious cycle has developed over decades and insulin resistance is now the main stimulus to your high insulin levels. Reducing carbs may not be the most effective treatment. Why? Because your problem is the insulin resistance. Lowering carbs will lower insulin and reduce the vicious cycle, but this cycle has been running for decades.

So what do you need to do? Remember that the question of insulin resistance is mostly a question of ‘when to eat’. Therefore, to break resistance, you need a sustained period of low insulin. This means that fasting will be more effective here than simple carb restriction. You will also need time, because it took time to develop and will require time to resolve.

Example 4 – Suppose your friend takes fibre supplements and loses weight. But it doesn’t work for you. Why? Because your friend’s problem may be excessive carbs and fibre will help reduce the insulin spikes associated with carb intake. However, if your problem is not that, then increased fibre won’t work so well.

Example 5 – Why did the Asian Rice Eater of the 1990’s not develop obesity? At that time, China was eating extremely high carbohydrate (white rice) diets. But they also ate virtually no sugar, very little animal protein, high vinegar (pickled vegetables), high fibre, and no snacks. That means that all the other pathways to insulin were shut down as they were only eating rice. They ate lots of protective factors. They did not eat constantly, so did not develop insulin resistance. They had almost no sugar and therefore did not develop insulin resistance. The end result? No obesity.

Example 6 – Suppose you eat a diet very high in unrefined starches, like sweet potato. At the same time you severely restrict animal protein. Will that work? It sure could. This increases carbs, yes, but decreases animal protein. You also significantly raise dietary fibre. This may be enough to sway the balance and decrease insulin which will lead to weight loss.

I should make clear that I am not anti-carbohydrate. That is only one piece of the puzzle – although refined grains and sugars tends to be a rather large part of the puzzle. They are certainly obesogenic, but there are other ways to compensate so that overall insulin does not increase. I’m anti-hyperinsulinemia. Insulin causes obesity. If carbs raise insulin then carbs will cause obesity. But you can certainly tweak your carbohydrate heavy diet to lower insulin. After all, the Kitavans ate a very high carbohydrate diet and still had insulin levels lower than 95% of the Swedish population. The Okinawans ate at diet of almost 70% sweet potato with no obesity at all. Of course, both populations still ate virtually no sugar, and no refined grains (wheat).


The number one mis-diagnosis we see in our Intensive Dietary Management program is chronic stress/ cortisol confusion. We see people who come in and swear that they cannot lose weight. Then, upon taking a history, we find that some non-dietary factor is responsible for weight gain. For example, we may find somebody who is taking some anti-psychotic medications. Some of them increase insulin. Or we’ll find pain syndromes. Or sleep deprivation.

Well, no wonder dietary changes didn’t make any difference. That wasn’t their problem. It was the cortisol/ stress pathway all along.

While I wish I could write that we helped fix them, the unfortunate truth is that these problems are much harder to fix. While there are time tested ways of reducing stress and cortisol levels, most patients simply do not take our advice to look into mindfulness mediation/ prayer/ religion/ yoga/ acupuncture/ massage. They came to a diet clinic and got advice to meditate. They look at me or Megan like we have two heads.

There is, however, good evidence that things such as mindfulness mediation can have an effect on weight loss.

At the University of California, San Francisco, a trial was done with mindfulness meditation and showed that they could reduce cortisol levels. This is no surprise since meditation has been done for thousands of years as a stress relieving method. This decrease in cortisol was closely paralleled by a decrease in abdominal fat.

The important thing to know about it is that meditation does not change the actual stressor. For example, suppose your boss is driving you crazy. You will be under a lot of stress. Meditation won’t change that one bit. What it will change is your body’s response to the stress. In the end, that is what is important. By decreasing the cortisol response, there is a decrease in abdominal fat. Your boss is still the jerk he was before. You have only changed your body’s response to this stressor.

One final thought about stress relief. It’s always a little amazing to me how far organized religion is ahead of the game. Think about the practices they preach. Prayer (similar to meditation). Belief in a higher power/ confession (stress relief). Weekly ceremonies, like mass (sense of community and continuity – important for stress relief). Small group session (friendship and sense of belonging – stress relief). Fasting. Yes, fasting. All of these practices that are so important for good health have been established thousands of years ago.

By The Fasting Method

For many health reasons, losing weight is important. It can improve your blood sugars, blood pressure and metabolic health, lowering your risk of heart disease, stroke and cancer. But it’s not easy. That’s where we can help.

Jason Fung, MD

By Jason Fung, MD

Jason Fung, M.D., is a Toronto-based nephrologist (kidney specialist) and a world leading expert in intermittent fasting and low-carb diets.

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