What to consider when eating LCHF: short-term and long-term risks
LCHF stands for Low Carbohydrate High Fat (Low Carb High Fat) and is a type of low-carbohydrate diet, which means eating less carbohydrates and more fat and protein. As a rule, this means eating less than 100 g of carbohydrates per day. If you eat 20 g of carbohydrates per day, it is called ketogenic diet. In fact, at 20 g of carbohydrates per day, the breakdown of fats becomes so strong that the concentration of ketones (ketone bodies) in the blood rises markedly.
Ketones are formed namely during the breakdown of fat and ketones can be used as an energy source in the body. If you eat 100 g of carbohydrates per day, you eat a so-called “liberal LCHF”. So if you eat 20 g of carbohydrates per day you eat a “strict LCHF” (also called ketogenic diet).
Read more about How to Eat LCHF
Low-carbohydrate diet was actually born with the famous Dr. Atkins and his “Diet Revolution” (Food Revolution). Dr. Atkins was an American cardiologist who advocated low-carbohydrate diets. It’s been over 30 years since the publication of Dr. Atkins Diet Revolution and today low-carbohydrate diet is one of the most popular diets for those who want to lose weight.
There are a number of advantages of low-carbohydrate diet (LCHF), which has been discussed in the chapter Science behind LCHF. Adhering to a low-carbohydrate diet simply means eating and drinking anything, as long as the amount of carbohydrates is low (sugar and fast carbohydrates should preferably be avoided). This means, of course, that several common ingredients in food and drink must be severely restricted (e.g. rice, pasta, soft drinks, lemonade, beer). Low-carbohydrate diet has been shown to be particularly effective for those who have diabetes.
Proponents of low-carbohydrate diet (LCHF) often argue the following: 6
- They often argue that the number of calories per day does not matter if you eat a low-carbohydrate diet. You don’t have to count calories as long as you reduce the amount of carbohydrates. It is therefore considered that the number of calories is not interesting, but rather the amount of carbohydrates in the food.
- They often argue that the more carbohydrates the food contains, and therefore you should eat more fat and more protein in order to be satisfied with the meal.
- Often they claim that Carbohydrates (sugar) are biochemically disadvantageous, while fats have a better effect on metabolism. It is said that the body’s energy burning becomes higher by fat, compared to carbohydrates (sugar). The higher the energy burning, the more you lose weight.
- They also claim that carbohydrates are addictive, and because you gain weight from carbohydrates (sugar), sugar poses a risk to the health of the body. 7 They argue that when you eat carbohydrates, insulin is released that makes you build up fat (especially from carbohydrates) and stops breaking down fat. This means that insulin is part of the explanation for gaining weight from foods rich in carbohydrates (sugar).
There is no doubt that the low-carbohydrate diet is effective for those who want to lose weight. There is also no doubt that low-carbohydrate diet is effective in type 2 diabetes, overweight and obesity. Read our review of Science behind LCHF. However, there is no evidence for several parts of the above claims. Several, or parts of the claims, remain to be investigated. For example, most studies at LCHF show that participants who eat LCHF actually reduce their calorie intake quite sharply (without instructing them to reduce calorie intake). This is probably connected with LCHF being more saturated because fat and protein are more satiating than carbohydrates.
Either way, low-carbohydrate diet is effective for losing weight, for getting better blood sugar, lower insulin levels and lower blood pressure. However, it should be mentioned that Mediterranean food is very much comparable to LCHF in terms of these effects.
Any weight loss leads to tissue loss
More and more people have today realized that training (physical activity) is not very effective for those who want to lose weight. There is no doubt that physical activity is healthy, but for weight loss it is rather ineffective. Relaying the diet is significantly more effective and, as a rule, it involves one of the following:
- You eat less food. This is called caloric restriction (low-calorie food, starvation diet). This is rarely a sustainable method.
- You eat low-carbohydrate diet (LCHF) and then eat until you are satisfied. This is an effective method.
- Man eats Mediterranean diet (Mediterranean diet). This is an effective method.
- Man eats low-fat diet. This means reducing the amount of fat in the food. This is not an effective method of losing weight.
There are consequences of limiting their food intake. Reducing the intake of carbohydrates, fats or all nutrients, can lead to excessive intake of certain nutrients. In principle, all diets that lead to weight loss lead to the following:
- You lose fat tissue, which makes you lose weight. This is a desired effect.
- Man loses muscles, skeleton and other tissue. This is an undesirable effect of weight loss.
You don’t want to lose muscle, skeleton and other tissue — it’s fat you want to reduce. Unfortunately, today it is not possible to lose weight without losing other tissue too and this is especially pronounced for those who lose weight alone with the help of diet and who do not eat the necessary nutritional supplements. From this regard, physical activity is important, since continuous physical activity strengthens muscles and skeleton. Nutritional supplements may still be needed.
Nutritional content of low-carbohydrate diet (LCHF): does LCHF contain sufficient nutrition, vitamins, minerals, etc.
An American study investigated whether strict LCHF (ketogenic diet) complies with the guidelines for daily intake of various nutrients by the US Food Administration (which is similar to the Swedish Food Administration). 8 Compared prescriptions and guidance presented in books on LCHF/Ketogenic diet with guidelines from the Swedish Food Administration. The study showed that LCHF/ketogen diet often results in eating fewer calories (between 1152 and 1627 kcal daily, according to Freedman et al) and this is also consistent with most clinical studies that tried LCHF.
It also notes that the low carbohydrate diet (LCHF) is rich in fat, especially saturated fat, which was previously thought to be harmful, but now we know that this is not the case.
Low carbohydrate diet is rich in protein, which is part of the explanation for saturation (protein is more satiating than both carbohydrates and fats). Unfortunately, low carbohydrate diet seems to offer too little Vitamin E, Vitamin A, thiamine (thiamine), vitamin B6, folate (folic acid), calcium, magnesium, iron, potassium and fiber. In fact, there are studies that show that much of this is true, for example Gardner et al (JAMA, 2007).
This means that those who eat strictly LCHF (ketogenic diet) may need replacement (nutritional supplements). In the pharmacy and in other stores, various multivitamin preparations are sold, which work just fine. However, a varied and useful LCHF diet may be sufficient to cover needs.
If you have gout
Eating strict LCHF (ketogenic diet) can lead to the fact that the concentration of urate (uric acid) in the blood rises. Many cases of gout are due to precisely high concentrations of urate in the blood. Therefore, caution should be exercised with LCHF if you have gout.
Bones, osteoporosis and fractures
The quality of the bones depends on several nutrients and some of these may be in deficit if you eat LCHF. Therefore, if you eat LCHF over a long time, there is (possibly) reason to consider a nutritional supplement. However, there are no studies showing an increased risk of fractures or an increased risk of osteoporosis. 9
Cancer and LCHF
Low-carbohydrate diet can mean eating less fruits, fiber and vegetables. It certainly does not have to mean it; it is perfectly permissible to eat as much fiber and vegetables as much as possible with LCHF. However, fruit is rich in fruit sugar (fructose), which is converted into ordinary sugar (glucose) in the body. Many advocates of LCHF believe that fruit should be seen as natural sweets and thus eaten in small quantities. It is quite common for books and websites about LCHF to recommend strong restrictions on fruit.
There are a wide range of studies that show that high intake of fruits and vegetables is associated with lower risk of cancer and better immune system. Unfortunately, there are no randomized clinical trials, which means that we cannot ensure whether the relationship is genuine or “just an association”. In addition, no clinical trial with low-carbohydrate diet has been ongoing long enough to investigate how it affects the risk of cancer.
In other words, today we do not know whether LCHF increases or reduces the risk of cancer. There are simply no studies. At present, however, there is no evidence that LCHF increases the risk of cancer.10
It should be pointed out that the sugar in fruit does not give the same rise in blood sugar and insulin as other forms of sugar. Fruits certainly contain sugar (fruit sugar) but the effect on blood sugar and insulin is much less than normal sugar. We therefore recommend that everyone who eats LCHF eat fruit regularly. Read more about fructose and its effects on weight.