Tuesday, November 16, 2010

Myth: For weight loss Calorie reduction is what matters. All diets will result in same losses, provided same calorie reduction is done.

Fact: Not all diets are created equal for losing weight.
Fact: Not everybody reacts to diets the same way. Some people have trouble gaining weight, others have trouble losing weight. On an average men find it easier to lose fat than women. Post menopausal women find it much harder to lose weight than other women. Older people find it tougher to lose weight compared to younger people. These all conditions are due to hormone status, and shows that calories are not the most important thing for fat loss. The 4 hormones which cause the above differences are Insulin, testosterone, estrogen, and human growth hormone.

Insulin is the most important hormone affecting weight gain and loss. Others are much less important.

Insulin is a storage hormone. While it is high the body is in storage mode. It will store all nutrients that are available. Glucose and fat are stored in the fat cells. It will not attempt to use the fat stored in the fat cells. The body will get all its energy from glucose.

Insulin's basic function is not getting rid of glucose, but humans, who are the only species to eat a whole lot of easily digestible carbohydrates, have evolved to use the insulin for this purpose. Glucose in blood is very bad. The tolerable limit is like a teaspoon in the whole blood of the body. People generally do eat a lot more than this amount. The body needs to get rid of the excess as fast as possible. This is where insulin helps. It instructs the body to use glucose only (fat metabolism is stopped). It instructs the body to store the glucose where ever possible. The glucose is stored as glycogen in muscles and liver. When glycogen stores are nearly full, glucose is converted in to saturated fats and stored in fat cells.

People with insulin resistance (ie lack of good sugar control, or (pre)diabetes) have constantly high insulin, as the body is not not responding to insulin properly and takes a lot more time to control glucose. The much longer high insulin period means that they have trouble losing fat. People with diabetes have different problem, they are so insulin resistant that even their fat cells don't respond to insulin. In this case fat cells will not take in anymore glucose/fat but will release fat. These people lose weight, because they cannot store anything anymore, including important nutrients, like proteins, calcium, etc.

So what do we learn here. Any diet that keeps the insulin low will be superior to a diet which does not do so. This is the reason why low carb diets work really well for weight loss. This does not mean that you can eat as much as you want and will still lose weight. It just means that given a calorie reduction the body will respond to low carb diets more easily.

Actually low carb diets in the initial few months will help people lose weight without calorie counting. The homeostasis system will prevent people from over eating.

There is even more benefits of going very low carb diets in the initial few months. This relies on the fact that we need glucose to store fat. The glucose molecule is cleaved into two glycerol molecules and fat is attached to each Carbon atom and converted into triglyceride. This triglyceride gets stored into fat cells. If there is not enough glucose this activity does not happen. There is another mechanism to store fat, in low glucose conditions, but that requires consistent very long low carb period. So for the initial few months the fat is free (only when doing very low carb <50gm/day, or coupled with very high physical activity). Not all people react well to very low carb diets. Diabetics may still need to use very low carb diets (be very careful, with blood sugar levels), even though they may not feel the best on it.

Eating less will help you lose weight, but the issue with eating less is that you are getting less nutrients also. If you stay too long without enough nutrients you will get nutritional deficiencies. So you want to eat highly nutritious foods during dieting. Contrary to popular belief grains are not very nutritious. You can compare them to any kind of vegetables/fruits/meat to see the difference. In addition high phytic content grains like wheat also prevent proper absorption of certain nutrients like Zinc, magnesium. It is important to up the vegetable/meat content of the diet during dieting. Vegetables are also much lower carb than grains and legumes.

Protein is a highly thermogenic nutrient. When diet contains a lot more protein then most of it gets converted to glucose. This conversion is highly thermogenic. It increases metabolic rate of the body. A higher metabolic rate increases the speed at which body burns fat. It also provides raw material, and helps prevent muscle loss. It is also very helpful in keeping a person satiated.

Fat is a good energy filler, as it does not affect insulin. It is good to increase fat percentage in the diet to help keep carbs in the diet low. Medium chain fatty acids are known to not get stored in the body, as they directly convert to ketones. Coconut oil is made up of mostly MCFA. This property is useful for keeping satiated without storing fat. Pastured Butter/Ghee provide important fat soluble nutrients, contrary to conventional advice that butter/ghee are bad for health.

Going low on calories can be detrimental, if done for long. As the body gets into starvation mode and reduces metabolic rate. This normally happens after 3 days, and then again at around 2 weeks of time. It is best to eat more once a week to keep this effect from kicking in. The duration is same even if we are fasting. This might sound counter intuitive but fasting increased human growth hormone, while eating less calories does not do so. The HGH production delays the reduction in metabolic rate.

It is not necessary to be all the time low carb. It depends on insulin resistance. If your insulin resistance is low, then you will get benefit of low carb even if you are low carb only some of the time, ie your insulin goes below the threshold required to metabolize fat some of the time. The benefits are increased if you go low carb in the evening, as the duration of low carb extends during the sleep. Fasting will also help as fasting is also a period of low insulin.

To Recap.
1) All people react differently to diets.
2) Hormonal status affects weight loss, particularly insulin production and resistance.
3) Low carb is better than high carb for fat loss.
4) Very low carb is better, for some people, and required for others.
5) Protein is important.
6) Think about nutrients during weight loss. You might go low on them.
7) Evenings are the best time to go low carb, if not doing it consistently.
8) Fasting is great, but start slowly and carefully.
9) Do not eat consistently the same amount everyday. Have cheat days ie high calorie days.

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