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9 popular weight loss diets under the microscope Diet

9 beliebte Gewichtsabbaudiäten unter der Lupe Diät

There are a lot of weight loss diets out there. Some focus on reducing appetite, while others restrict calories, carbohydrates or fats.

Since all of these diets claim to be superior to all other diets, it can be hard to know which of these diets are worth trying. The truth is that there is no such thing as "the best diet" for everyone - and what works for you may not work for someone else.

This article will take a closer look at the 9 most popular weight loss diets and the science behind these diets.

1 The Paleo Diet

The Paleo diet says that you should eat the same foods that our hunter-gatherer ancestors ate before the age of agriculture began. The theory is that most modern diseases can be linked to the Western diet and the consumption of grains, dairy products and processed foods.

While it's debatable whether this diet really encompasses the same foods your ancestors ate, it is associated with some impressive health benefits.

How this diet works: The Paleo diet emphasizes whole foods, low-fat protein sources, vegetables, fruits, nuts and seeds, while discouraging the consumption of processed foods, sugar, dairy and grains.

Some more flexible versions of the Paleo diet also allow dairy products such as cheese and butter, as well as root vegetables such as potatoes and sweet potatoes.

Weight loss: Several studies have shown that the Paleo diet can lead to significant weight loss and a significant reduction in waist circumference (1, 2, 3, 4).

In studies, people who followed this diet automatically ate fewer carbohydrates, more protein and between 300 and 900 kcal less per day (1, 2, 3, 4).

Other benefits: This type of diet appears to be effective in reducing risk factors for heart disease such as high cholesterol levels, high blood sugar levels, high blood triglyceride levels and high blood pressure (5, 6, 7).

The cons: The Paleo diet eliminates grains, legumes and dairy from the diet, which are healthy and nutritious.

Summary: The Paleo diet emphasizes whole foods and eliminates grains and dairy from the diet. It has several health benefits, including weight loss.

2. the vegan diet

The vegan diet eliminates all animal foods from the diet for ethical, environmental or health reasons. Veganism is also associated with opposition to animal exploitation and cruelty to animals.

How this diet works: Veganism is the strictest form of vegetarianism. In addition to eliminating meat from the diet, dairy products, eggs and foods derived from animal sources such as gelatin, honey, albumin, whey, casein and some forms of vitamin D are also removed from the diet.

Weight loss: A vegan diet appears to be very effective in helping people lose weight - often without the need to count calories - as it is low in fat and the high fiber content can help keep you fuller for longer.

Vegan diets are consistently associated with lower body weight and lower body mass index (BMI) compared to other diets (8, 9, 10, 11, 12).

An 18-week study showed that people who followed a vegan diet lost 4.32 kilos more weight than those who followed a control diet. The vegan group was allowed to eat until they were full, while the control group had to restrict their calorie intake (13).

However, calorie for calorie, vegan diets are no more effective for weight loss than other diets (14). The weight loss observed with vegan diets is primarily associated with reduced calorie intake.

Other benefits: Plant-based diets are associated with a reduced risk of heart disease, type 2 diabetes and premature death. (15, 16, 17, 18, 19).

Limiting processed meat consumption may also reduce the risk of Alzheimer's disease and death from heart disease or cancer (20, 21, 22, 23, 24).

The disadvantages: Because vegan diets completely eliminate all animal foods from the diet, such diets can be low in certain nutrients such as vitamin B12, vitamin D, iodine, iron, calcium, zinc and omega-3 fatty acids (25, 26, 27, 28, 29).

Summary: Vegan diets exclude all animal products. They may promote weight loss due to lower calorie intake and reduce the risk of various diseases.

3. low-carbohydrate diets

Low-carb diets have been popular for decades - especially for weight loss. There are different types of low-carb diets, but all involve limiting carbohydrate intake to between 20 and 150 grams per day.

The primary goal of these diets is to force the body to use more fat instead of carbohydrates as its primary energy source.

How this diet works: Low-carb diets include unlimited amounts of protein and fat while drastically limiting carbohydrate intake.

When carbohydrate intake is very low, more fatty acids are released into the bloodstream and transported to the liver, where some of them are converted into ketones. In the absence of carbohydrates, the body can use these fatty acids and ketones as a primary source of energy.

Weight loss: Numerous studies suggest that low-carbohydrate diets are extremely helpful for weight loss, especially for overweight and obese people (30, 31, 32, 33, 34).

They also appear to be very effective in reducing the dangerous belly fat that can accumulate around the organs (35, 36).

People who follow very low-carbohydrate diets usually achieve a state known as ketosis. Many studies note that ketogenic diets result in more than double the weight loss compared to calorie-restricted diets and low-fat diets (35, 36, 37, 38, 39).

Other benefits: Low-carbohydrate diets tend to reduce appetite and hunger, resulting in an automatic reduction in calorie intake (40, 41).

In addition, low-carbohydrate diets can have a positive effect on many risk factors for diseases such as high blood triglyceride levels, high cholesterol levels, high blood sugar levels, high insulin levels and high blood pressure (34, 43, 43, 44, 45).

The disadvantages: Low-carb diets are not for everyone. Some people feel great on these diets, while others feel miserable. Some people may also experience an increase in bad LDL cholesterol levels (46).

In extremely rare cases, very low-carbohydrate diets can lead to a serious condition called non-diabetic ketoacidosis. This condition appears to be more common in breastfeeding women and can be fatal if left untreated (47, 48, 49, 50).

However, for most people, low-carbohydrate diets are safe and harmless.

Summary: Low-carbohydrate diets severely restrict carbohydrate intake and cause the body to use fat as an energy source. They support weight loss and are associated with many other health benefits.

4 The Dukan diet

The Dukan diet is a high protein, low carbohydrate weight loss diet that has four phases - two weight loss phases and two maintenance phases. How long you stay in each of these phases depends largely on how much weight you need to lose. Each of these phases has its own dietary pattern.

How this diet works: The weight loss phases are primarily based on eating unlimited amounts of protein-rich foods and the mandatory consumption of oat bran.

The other phases include adding non-starchy vegetables, followed by a few carbohydrates and some fat. Later phases include fewer and fewer protein-only days to maintain the new weight.

Weight loss: In one study, women following the Dukan diet ate about 1000 kcal and 100 grams of protein per day and lost an average of 15 kilos in weight within 8 to 10 weeks (51).

Many other studies also show that high-protein, low-carbohydrate diets may have significant benefits for weight loss (52, 53, 54, 55). These include a higher metabolic rate, a reduction in the levels of the hunger hormone ghrelin and an increase in the levels of several satiety hormones (56, 57, 58, 59).

Other benefits: Aside from weight loss, no other benefits of the Dukan diet are found in the scientific literature.

Disadvantages: There are very few high-quality scientific studies that have looked at the Dukan diet.

The Dukan diet limits both fats and carbohydrates - a strategy that is not based on scientific evidence - quite the opposite: consuming fat as part of a high-protein diet appears to increase metabolic rate compared to both low-carbohydrate and low-fat diets (60).

In addition, the rapid weight loss caused by severe calorie restriction also tends to cause a significant loss of muscle mass (61).

The loss of muscle mass and severe calorie restriction can also cause the body to conserve energy, making it easier to regain the lost weight quickly after the weight loss phase ends (62, 63, 64, 65).

Summary: The Dukan diet has not yet been studied in high-quality human trials. The diet may cause weight loss, but it may also lower metabolic rate and lead to loss of muscle mass.

5 The ultra low-fat diet

An ultra-low fat diet limits the daily consumption of fat to less than 10% of the daily calorie intake. In comparison, a low-fat diet includes about 30% of the daily calorie intake in the form of fat.

Studies have shown that this diet is ineffective for long-term weight loss. Advocates of the ultra low-fat diet, on the other hand, claim that traditional low-fat diets are not low-fat enough, and that fat intake must be less than 10% of total calories to provide health benefits and promote healthy fat loss.

How this diet works: An ultra low-fat diet includes 10% or less of total calorie intake in the form of fat. This diet is primarily plant-based and includes only a limited amount of animal products (66). For this reason, it is generally very high in carbohydrates - about 80% of calories - and low in protein - about 10% of calories.

Weight loss: This diet has been shown to be very successful for weight loss in obese people. In one study, obese subjects lost an average of about 63 kilos on an ultra low-fat diet.

Another eight-week study with a diet that included 7 to 14% of total calorie intake in the form of fat showed an average weight loss of 6.7 kilograms (68).

Other benefits: Studies suggest that ultra low-fat diets may improve several risk factors for heart disease including high blood pressure, high cholesterol levels and markers of inflammation (69, 70, 71, 72, 73, 74).

Surprisingly, this high-carbohydrate, low-fat diet can also lead to significant improvements in type 2 diabetes (75, 76, 77, 78).

In addition, the diet may slow the progression of multiple sclerosis - an autoimmune disease that affects the brain, spinal cord and optic nerves of the eyes (79, 80).

The downsides: Fat restriction can lead to long-term problems, as fat plays important roles in the body. These include building cell membranes, producing hormones, and aiding the absorption of fat-soluble vitamins.

In addition, an ultra-low fat diet limits the consumption of many healthy foods, limits dietary variety and is very difficult to maintain.

Summary: An ultra low-fat diet includes less than 10% of total calories in the form of fat. It can cause significant weight loss and have impressive benefits for the heart, type 2 diabetes and multiple sclerosis.

In the second part of this article, we will take a closer look at the Atkins Diet, the HCG Diet, the Zone Diet and Intermittent Fasting.

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