Weight gain and weight loss difficulties: the Set-Point Theory (part 2)

By Kanya Said:

Many of us try to lose weight but we find it very hard. We often lose some weight at the beginning. After that, we get very tired and we give in to the food offered, especially in the Kurdish culture where it is considered rude for a guest to say ‘no’ when food is served, and we gain weight again. We end up weighing more than when we started our diet. Many fall into a yo-yo dieting trap that is hard to get out of. This behavior is not due to a weakness in the person trying to lose weight, nor is it all down to the Kurdish food – the culture that surrounds us. But it is well explained by a theory called the Set-Point Theory.

The Set-Point Theory

Food intake and energy expenditure are balanced in each person so that the individual is able to keep their weight at a certain ‘set-point’. This is determined by some factors that are:

Genetics: We have a genetic ability to be drawn to a certain weight. Some of us can eat a lot without gaining weight and others can gain weight very easy by not exercising much during a period.

Long term changes in our body weight: If we eat more for months, we will weigh more in the end.

Obesogenic environment: These are some of the factors mentioned in the previous article that brings up today’s culture that favors eating out at restaurants and café visits but makes it hard to exercise and work out.

This set-point changes upwards easily (it’s easy to gain weight) and it is hard to force it down.

The reason is that the brain, through a structure called the hypothalamus, is regulating our metabolism and our behavior strongly to keep its own goal weight. In other words; there is a strong physiological force that defends your weight. In the short term it does not matter if we eat more or exercise less because the body keeps its weight with different compensation mechanism. However, if we eat more for a long time and gain weight, these strong forces will work to try to keep the new weight.

Obesity is about the brain defending a higher body weight, rather than not being able to regulate it. The person has a high set-point. An individual who suffers from obesity is in an energy imbalance and because of the factors mentioned above he/she has a higher set point that contributes to the high weight.

There is an interaction between an obesogenic environment and a homeostatic control system that, when in imbalance, contributes to the obesity pandemic seen today around the world, and particularly in Kurdistan with its improving economic situation and growing food-culture with more availability of food and more fast-food.

Proof that there is a set-point:

We can keep our weight even if we have changes in calorie intake (short term – a matter of days)
Changes in diet or lifestyle are rather ineffective when we want to lose weight.
We always return to our set point after a diet and free amounts/over intake of food (short term).

Set-Point Theory and long-term effects of diets

We will assume that a person who has a normal food intake, where he can eat as much as he wants, goes on a diet.

What will happen is that the person will lose some weight in the beginning, mostly due to loss of water with the decreasing glucose and glycogen storage, but then we will see strong forces that lead to two things: first, the metabolism will decrease and, second, the reward-system in the brain will be hyperactive which makes the person think of food constantly (the person will be “obsessed with food”).

These are pure genetic and evolutionary forces that have developed to prevent starving.

When the person goes back to eating as much as he likes (ending the diet) the body will have less need of energy (the metabolism is low from the under-eating period) and they will have huge cravings for food (physiological behaviorism).

This will result in weight gain and most often the person gains more than when he started the diet. The cycle of food craving will make the person eat even more; adding to the weight gain. If the person starts to eat normally again there will be a small weight loss but he will never go back the original weight. Now the person has a new higher set-point (see the image below):

No studies show that if one increases food intake then the metabolism will increase in response; but, if you cut down on the calorie intake, the metabolism will decrease for sure to prevent starvation. Between 25-55 years a person gains 8 kg due to a net-imbalance of energy intake and expenditure.

The factors that affect the energy intake vs. the energy expenditure are the basal metabolic rate (BMR), physical exercise and adaptive thermogenesis (keeping the body temperature).

BMR is the minimum amount of energy needed for a resting body to stay alive. There are factors that affect BMR: infections, growth, body size, pregnancy, menstruation and breastfeeding increase it while aging decreases it. Men have a higher BMR than women.

Other factors that change the BMR can be body temperature changes, food intake (if you eat less, the BMR goes down), emotions and hormones (increased thyroid hormone raises the metabolism such as adrenalin/stress hormone).

A question we can ask is: why do we eat?

To balance our energy expenditure
For pleasure or activating the reward system
Stress
Social factors
Boredom

What is the brain’s role?

The hypothalamus in the brain works as an adipostas (adipose means fat tissue) where it balances the fat tissue levels in the body. It’s seen as a hypothetic mechanism that tries to keep most peoples bodyweight within a small interval. Nutrients and hormones affect the hypothalamus, the brainstem and higher CNS-centers such as the reward system. These CNS-systems affect the hypothalamus that decides our energy expenditure in a way of: basic metabolism, physical activity, and thermogenesis. This also affects our behavior, including appetite and food-seeking.

So, what are the available treatments?

There are few drugs on the market today that work in an effective way to help in the fight against weight loss. Most of the drugs seen in Kurdistan that are very active in advertising themselves are very weak and seen as herbal drugs or phytopharmaceuticals. The majority of these drugs work on raising the BMR. It’s important to remember that when we raise the basal metabolic rate we also increase our appetite in most cases and so we can actually end up eating more. Therefore we must be aware of the products sold in Kurdistan.

One of the most widely imported drugs from, for example, Dubai into the biggest Kurdish cities such as Hawler and Slemani is called orlistat (Xenical).

This drug works in such a way that binds to the fat in the food you eat and prevents it from being absorbed in the intestine so you have oil in your faeces (stool).

Some other more powerful drugs on the Kurdish market affect your mood; when you are very happy you don’t want to eat as much. And they raise the heartbeat so you are more active. However they also cause cardiovascular diseases and, due to this, are no longer on the Swedish drug market.

According to studies surgery is the best option for an effective weight loss. There are many different types of surgery but it should only be considered in cases of severe obesity with BMI mostly above 40. With the surgery can come many complications and, if the patient doesn’t change his eating habits, there will be a weight gain for sure.

The only effective treatment for weight loss is to cut down on the daily calorie intake and to exercise more (daily power-walks, for example, raise the BMR). This applies to all diets where you eat fewer calories.

An effective way is to decrease carbohydrate intake in the diet because then you will get a change in the hormones controlling energy balance and hunger. If you base your food intake on meat and vegetables and eat fewer carbohydrates, you can still keep your metabolism at a more stable level and will feel less hunger due to the meat which starts satiety signals in the stomach.

Studies show that a quick weight loss in the beginning followed by a controlled slow weight loss can give better results in the long term, with patients being more successful at keeping their goal weight.

When on a diet one should know that it is normal to be tired, cold and to think about food. This is the body’s way of reacting and, therefore, it is hard to push down a set-point but it is still possible. To raise a set-point can take a few weeks but to push it down requires that one is controlling his/her food intake for several weeks/a year. It is possible but one has to be patient.

It might take you no more than a few hard-working months to reach your dream weight but – to be able to fulfill your New Year’s resolution next year – you need to control yourself all year round and in the years to come.

Part 1

Kanya Said is a Dentistry and Medical student at Göteborg University, Sweden. Originally from Slemani, Kurdistan, her aim is to return home and help in the development and improvement of the Health Care system in her homeland. Kanya is currently, besides her Medical studies, writing a series of books; the first one being a ‘Manual of Medicine’ in the Kurdish language, and she is planning her Master degree within immunology and nutrition.