Why is it difficult to lose '2 kg left' on a diet?

There are various ways to lose weight, such as 'exercise', 'meal', 'improvement of life', but any method that stands out as a wall is that 'it is difficult to lose weight from a certain line'. There should be a lot of people who give up because of this trap. Professor Peter Rogers, who studies behavioral neuroscience at the University of Bristol, cites two reasons why he wouldn't lose weight when he was '2 kg left'.

Weight loss: here's why those last few pounds can be hardest to lose – according to science

The first reason mentioned by Professor Rogers is the slowing of metabolism . When you lose weight, you need less calories to maintain and move your body.

As a specific example, Professor Rogers envisions a 45-year-old man with a height of 175 cm, a weight of 90 kg, and a moderate amount of activity. If this person wants to lose weight to 75kg in half a year due to dietary restrictions, he needs to reduce his daily calorie intake from 3200kcal to 2270kcal. The weight loss range is 15 kg, but as mentioned above, it is difficult to lose weight, so it is necessary to set a goal such as 2.6 kg on average for the first 5 months and 1.8 kg for the last month. There is. If you want to maintain your target weight of 75 kg, it is not enough to return the calorie intake to the conventional 3200 kcal, and it is necessary to keep it at about 2780 kcal.

The second reason is increased appetite associated with weight loss . A hormone called leptin conveys the amount of fat accumulated in the body to the brain, and when the amount of fat increases, the amount of leptin also increases and the appetite decreases, but on the other hand, when the amount of fat decreases, the 'brake' of leptin comes off. You will feel strongly hungry.

In an experiment conducted in the past, when a subject invited to a pizza for lunch was told to 'eat comfortably until full', he ate 1580 kcal, whereas 'eat as much as possible' It is known that the subject who was told ate twice as many calories as needed per day. In other words, humans can eat much more than they can get a 'moderate satiety.'

This 'fullness' is determined by the amount of fat, carbohydrates, and proteins and the amount of the whole meal, and it has been known that a feeling of fullness can be obtained when the amount of fiber is high. This means that you will not eat too much fibrous vegetables and fruits. Professor Rogers pointed out that if the one eaten in the above experiment was not a pizza but an apple that only had 50 kcal per 100 g, it would not have been able to eat 1580 kcal (3 kg or more of apples).

However, humans feel 'delicious' when they have a high energy density, such as pizza with about 280 kcal per 100 g, chocolate with about 500 kcal per 100 g, and potato chips. High-calorie foods are delicious and have a low feeling of fullness per calorie, so you end up eating too much. However, recent studies have shown that eating high-calorie foods does not seem to satisfy a certain level of satisfaction, says Professor Rogers, ``You can reduce calorie intake without affecting satisfaction. I think.” For example, eating one 95kcal strawberry yogurt instead of one 250kcal strawberry cake may slightly reduce your satisfaction, but if you continue to do so, you will start to choose low-calorie habits. , May lead to weight loss.

The problem is that it is difficult to resist the desire to 'eat delicious and energy-rich foods.' Since it is difficult to maintain self-control for a long period of time, this may also result in strengthening the recognition that 'the remaining 2 kg cannot be reduced', Professor Rogers points out.