The High-Fat Regimen vs. The High-Carbohydrate Regimen
Oliwia Kaczmarek
2026-03-25
4 min. read
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1 zdjęcie
2032
The search for an answer to the question of which of these two diets is better is nothing new... As early as 1860, the American businessman William Banting mentioned the benefits of reducing carbohydrates in the diet, such as reducing hunger or significantly reducing body weight... The early 20th century was dominated by studies showing the ergogenic properties of carbs, but in the 1970s, there was the protein-fat revolution, which was started by Dr. Atkins... About 10 years later, recommendations appeared to limit the amount of fat in the diet, which was the result of many studies showing a correlation between fat consumption and obesity and the development of civilizational diseases... Nowadays, the paleo diet and the ketogenic diet are gaining more and more popularity.
Which Nutrients are Stored as Fat
According to the first law of thermodynamics, energy cannot be created or destroyed, and everything we eat enters our body. However, the human body is not an isolated system, so consuming specific nutrients can cause different physiological effects. For instance, ingesting carbohydrates can lead to an increase in blood glucose levels, which can pose a health risk. To stabilize blood glucose levels, the body releases insulin. Transforming carbohydrates into fat is a highly energy-consuming and inefficient process, so carbohydrates are directed to muscles where they are used as an energy source. Limiting carbohydrate intake can help maintain a high fat-burning rate, but it also requires consuming more fat to provide the body with adequate energy for optimal functioning. An example of these relationships is the study by Dr. Kevin Hall, in which participants were divided into two groups - one group followed a high-fat diet, while the other group obtained most of their energy from carbohydrates. The researcher used the metabolic chamber to measure how much fat the participants used as an energy source. The results of this study can be interpreted in two ways - in the high-fat diet, more fat was used as an energy source, while in the high-carbohydrate diet, more fat was burned than provided by the diet. However, these results should be interpreted with caution, as they do not necessarily mean that a high-fat diet is better than a high-carbohydrate diet.
Key role of protein
While there are many examples of positive effects on body size that can be found from the use of both high-carbohydrate and high-fat diets, the best way to make a fair comparison is to refer to scientific research. Below are a few examples along with their detailed dietary specifications. It may seem that the fat-rich diet has an advantage over the high-carbohydrate diet, but the diets are sometimes not equal in terms of calorie content, and even less so is maintaining the same protein intake. Many fat-rich products also contain a large amount of protein. It is difficult to prepare a fat-rich dish that is not also rich in protein. With carbohydrate-rich dishes, it is more difficult to prepare a dish that is rich in protein. This fact is of great importance, as protein is responsible for suppressing the feeling of hunger, stimulating metabolism, and building muscle. What happens if one equates a high-carbohydrate diet with a high-fat diet in terms of protein content? The answer to this question was sought in a study from 2006. The results showed that the fat loss was the same for both diets (no statistically significant differences). Similar results were obtained in other studies that took into account similar protein amounts - in these conditions, the difference between the diets is minimal.
Efficiency
The most comprehensive study that evaluated the impact of a high-fat diet on efficiency lasted for 4 weeks and was conducted by Dr. Stephen Phinney. The study examined the participants' endurance capabilities and adaptation to using fat as an energy source after transitioning to a ketogenic diet. Despite the near-total absence of carbohydrates in the diet, the efficiency of the participants did not change after 4 weeks of dieting, indicating a neutral effect of the high-fat diet in this context. However, these are average data and do not take into account individual factors. In the case of one participant, a significant increase in efficiency was observed, with the time to exhaustion increasing by 84 minutes! In the case of two other participants who switched to a high-fat diet, the time they could run was reduced by 48 and 51 minutes, respectively. This shows that individuals may respond differently to the diet, some will improve their results by adhering to a high-fat diet, while others will improve their results by adhering to a high-carbohydrate diet.
The advantages of a carbohydrate-focused diet
There are several notable benefits of a carbohydrate-focused diet: – increased glycogen levels and enhanced ability to utilize it; – improvement of physical performance during intense training sessions; – elevation of hormone levels: IGF-1, leptin, and thyroid hormones (T3); – reduction of cortisol levels.
The benefits of a high-fat diet
The advantages of following a high-fat diet include: – improved management of hunger sensations; – easy provision of adequate protein in daily meals; – reduced insulin levels; – elevated levels of ketone bodies and hormones such as glucagon and catecholamines.
The definitive decision on diets
The debate surrounding these forms of nutrition is heated, as there's no conclusive decision as to which is better -- the restriction of both fat and carbohydrate in the diet has its disadvantages and advantages, and the correct application of these macronutrients can increase effectiveness.
