Is cutting on carbs necessary during body fat reduction? Part II

In one of my previous articles I wrote about the supposed neccesity of decreasing the intake of carbohydrates in order to cause the reduction of body fat. That article resulted in many controversies and provoked many comments. It's high time to write more about this issue referring to scientific studies, which seem to be quite surprising according to many common beliefs.

Is cutting on carbs necessary during body fat reduction? Part I

Regarding the previous part of this article

I will only remind you, that in the previous article I indicated that the scientific studies, in which the low-carb (LC) diets seemed to be more efficient than high-carb (HC) ones, were often designed in a way that the content of protein was significantly higher. It could explain higher efficiency of low-carb diets. I depicted it with the results of an experiment, in which that aspect was taken under consideration and where the authors planned four various diets: two with low and two with high supply of carbohydrates, and the additional factor differentiating the diets was the supply of proteins set on the same, or different level for HC and LC. It occurred that better effects could be observed when the content of proteins was higher, independently from the supply of fat and carbohydrates. You can read the whole article under the link below:

Is cutting on carbs necessary during body fat reduction? Part I

In this part of the article I would like to refer to two other aspects: the influence of consuming large amount of carbohydrates on insulin sensitivity and the influence of a well-balanced highly-carbohydrate diet on the level of body fat (comparing to the Western diet, poorer in carbohydrates).

Carbohydrates and insulin resistance

There is a belief that states that carbohydrates cause insulin resistance, to be precise, the higher participation of energy from this this macro nutrient – the higher risk of decreasing insulin sensitivity. The remedy for this problem, or rather threat, are the carbohydrate restrictions, which are supposed to improve the insulin sensitivity. Well, practically speaking, it occurs that the situation is not that simple. Research shows that both, high intake of carbohydrates and high intake of fat may foster insulin resistance. Therefore, you shouldn't approach this matter in a dogmatic and thoughtless way. I will not write more about insulin resistance, as I wrote separate articles about it, two of which are linked below:

What is insulin resis and what forms doeas it have?

How to recognise insulin resistance?

An intriguing study

In this article I would only like to show that increasing the supply of carbohydrates in diet may also be the way of improving insulin sensitivity. It's worth adding, that I don't mean slight increase of the carbohydrate intake, but the amount of 70% of the daily supply of energy. The proof is the research with the use of the traditional Asian diet, lead by Dr William C. Hsu. At the beginning, all the volunteers ate traditional Asian diet (TAD) for eight weeks, then they were divided into two groups, one of which stayed with the current diet (TAD) and the other had the Western diet (TWD).

The assumptions of TWD and TAD

Before I present the results, I would like to describe both diets. The traditional Asian diet included:

  • high supply of carbohydrates (reaching up to 70%),

  • low supply of fat (about 15%),

  • low supply of animal-origin protein (about 20% of the daily protein intake),

  • optimal supply of fibre of 33g per day.

For a change, the typical Western diet was based on the following assumptions:

  • lower supply of carbohydrates than in TAD (50%),

  • moderate supply of fat (34%),

  • similar amount of protein (16%),

  • higher supply of animal-origin protein (60-80%),

  • low supply of fibre (13g).

I should add, that both diets had the same calorific content.

The results of the experiment – the introduction period

During the first eight weeks of the experiment, i.e. when all the volunteers followed the rules of the TAD, the results were following:

  • decrease of the total body mass,

  • decrease of the body fat (especially the fat within the abdomen cavity),

  • improving the insulin sensitivity,

  • improving the blood sugar control,

  • improving lipidogram.

The fact that introducing diet with such high supply of carbohydrates caused so many advantages may be surprising, according to common beliefs. But comparing the Asian and Western diets lead to even more interesting conclusions.

The results of the experiment – the comparative period

After eight weeks of using TAD diet, one part of the volunteers was assigned to the isoenergy TWD. It turned out, that the results in this group were following:

  • increased body mass,

  • increased level of body fat (especially the visceral fat),

  • decreased insulin sensitivity,

  • worse blood sugar level,

  • worse lipidogram.

To be honest, the diet with higher supply of carbohydrates turned out to be better from the body composition and health parameters connected with the insulin-glucose and lipid economy point of view. However, that's not the only intriguing study worth taking under consideration.

You can read more about the mentioned study under the link below:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4167335/

Summary

The highly-carbohydrate diet doesn't have to influence negatively insulin sensitivity, it may turn out to act in opposite way. What's more, you can lose weight efficiently on highly-carbohydrate diet! Even with extremely high supply of carbohydrates (reaching up to 70% of the daily energy supply). In the next part of this article, to complete the picture, I will present the results of a very precisely designed experiment, which compared the low-carb and high-carb diet during losing body fat!