5 Diets Confirmed by Scientists

5 Diets Confirmed by Scientists

We have studied several dozen serious research and put together a diet that accurately helps you lose weight. You only need to choose the diet that does not make you suffer and make it part of your life.

1. Atkins diet Atkins dietThis popular low-carb diet was developed in 1960 by cardiologist Robert C. Atkins. The diet includes several phases and is aimed at changing eating habits to healthier ones. 

What is the essence of the diet

The Atkins diet does not include calorie counting or portion control. The only thing to consider is grams of pure carbohydrates minus fiber.

The diet is divided into four phases:

  1. The first phase is the most severe, it lasts at least two weeks and allows you to lose 3-4 kg. At this time, you reduce the number of carbohydrates to 20 g per day, and 12-15 g of them are obtained from vegetables. You consume a lot of protein from poultry, meat, fish and seafood, eggs, cheese, while completely eliminating fruits, sweet pastries, pasta, cereals, nuts. It is necessary to give up alcohol and drink eight glasses of water per day.
  2. You continue to consume 12-15 g of carbohydrates from vegetables and avoid sugar, but gradually return some foods rich in healthy substances: nuts, seeds, berries. You lose weight and proceed to the next phase only when about 4.5 kg is left before your goal.
  3. You gradually introduce previously banned foods into the menu: fruits, starchy vegetables, whole grains. You can add 10 g of carbohydrates. But if you start to gain weight again, you need to return to normal at 20 g. In this phase, you remain until you reach your ideal weight.
  4. Any foods are allowed, but you continue to adhere to the principles of the diet. If you begin to gain weight, return to the previous phase.

What science says?

In 2007, Stanford University investigated the effectiveness of four popular diets: Atkins, Ornis, Zones, and LEARN (low-fat diet). After 12 months, those on the Atkins diet lost 4.7 kg, on the LEARN diet — 2.6 kg, on the Ornish diet — 2.2 kg, and on the Zona diet — 1.6 kg.

In general, many studies confirm the benefits and effectiveness of low-carb diets. For example, a recent scientific review of six studies showed that diets with a low glycemic index or low glycemic load allow you to burn an average kilogram more than others, positively affect body weight, amount of fat and cholesterol.

Another study found that high-protein diets with a low glycemic index help maintain weight.

But the diet with a sharp reduction in carbohydrate may have the following side effects:

  1. Headaches.
  2. Dizziness.
  3. Weakness.
  4. Constipation

Atkins diet is not recommended for people with kidney disease, women during pregnancy and lactation, as well as people with high physical activity.

2. Paleo diet

Paleo dietIn 2013, paleo-diet became one of the most popular in the world, although there is still no consensus among nutritionists whether this diet is useful or not. 

What is the essence of the diet

The paleo diet is based on products that our distant ancestors ate even before the advent of agriculture.

Supporters of the diet claim that, despite the thousands of years that have passed since that time, the human body still copes best with the food of hunters and gatherers.

The menu includes meat, fish, eggs, vegetables and fruits, nuts (except peanuts) and seeds. Ideally, the meat should be of animals grown in natural conditions, without the use of special feeds.

The diet completely excludes sugar, starchy vegetables, dairy and grain products, oils (except for cold-pressed olive, walnut and avocado oils), legumes, tea, coffee, carbonated and alcoholic drinks, fruit juices.

What science says?

In 2007, scientists compared the effects of paleo- and Mediterranean diets without calorie restriction.

After 12 weeks, people on the paleo diet lost an average of 5 kg (on the Mediterranean — 3.8 kg) and lost 5.6 cm at the waist (in the other group — 2.9 cm). On average, people from the paleo group consumed 451 kcal less per day than in the control group, and without any restrictions. In addition, their blood sugar levels returned to normal.

The benefits for the figure were confirmed in a 2009 study. For three months, one group adhered to paleo-diets, the other — the usual diet for diabetics. As a result, the former dropped 3 kg more than the latter.

The 2014 long-term study is also interesting. The persons were divided into two groups: for two years, some adhered to paleo-diets, others — a high-carb diet with a low amount of fat. The paleo-diet group lost more fat, especially abdominal fat, after 6, 12 and 18 months.Nutritionists call many possible dangers of paleo-diets, among which:

  1. Calcium deficiency due to a lack of dairy products.
  2. Deterioration of the kidneys due to the consumption of large amounts of protein and saturated fats.
  3. Increased risk of heart disease due to the consumption of large quantities of meat.

However, despite the possible negative effects of the diet, there are no studies proving obvious harm to health.

3. Vegan Diet

Vegan DietThe term “vegan” appeared in 1944 thanks to a group of vegetarians who formed the Vegan Society. They decided to stop exploiting animals in any form and refuse not only meat but also eggs and dairy products. 

What is the essence of the diet?

The vegan diet does not include meat and poultry, fish and seafood, eggs, dairy products, as well as dishes that may include components of animal origin: gelatin, casein, lactic acid.

Vegetable products are consumed without any restrictions. Vegans eat legumes, tofu cheese, nuts, seeds, vegetables, and fruits, drink coconut and almond milk.

What science says?

A 2013 randomized study showed that a low-fat vegan diet can significantly reduce weight.

After 18 weeks of research, vegans got rid of an average of 4.3 kg, while people in the control group got rid of 0.1 kg. The former also decreased cholesterol and blood sugar.

Scientists got similar results in 2005. After 14 weeks, people who gave up animal products lost 5.8 kg, and people who replaced saturated fats with carbohydrates (the NCEP diet) lost 3.8 kg. Also, vegans lost more than a centimeter at the waist.

A two-year study, completed in 2007, also confirmed the effectiveness of a vegan diet for weight loss. 64 overweight women followed either a vegan diet or an NCEP diet. As a result, after a year, vegans threw 4.9 kg, and participants on the NCEP diet — 1.8 kg. According to the results of two years, weight loss in the vegan group was 3.1 kg, and in the NCEP group — 0.8 kg.

The main danger of a vegan diet is a lack of vitamin B12, which is essential for human health and derived from animal products.

Deficiency of B12 can result in anemia, chronic fatigue, depression. In addition, a 2015 study found that deficiency of this vitamin increases the risk of heart disease in vegetarians. Therefore, following a vegan diet, it is advised to take supplements with B12.

As for protein, it can be obtained from plant products.

4. The Mediterranean diet with calorie restriction

The Mediterranean dietUnlike fast diets like grapefruit, the Mediterranean cannot boast of quick results. However, it is much more effective in the long run and helps maintain not only weight but also health. In addition, it is easier and more pleasant to follow this diet, which also affects its effectiveness. 

What is the essence of the diet?

Here are the basic principles of the Mediterranean diet:

  1. The diet is based on fruits and vegetables, whole grains, legumes, nuts, cheese, and yogurt. These foods can be eaten every day.
  2. Butter is replaced by olive and rapeseed.
  3. Red meat, eggs, and sweets should be eaten as little as possible but can be completely excluded from the diet.
  4. Fish and poultry should be eaten at least twice a week.
  5. You need to drink six glasses of water a day. Sometimes you can drink red wine.
  6. You need to add some exercise.

What science says?

Most studies on the Mediterranean diet relate to its health benefits. For example, Dr. Ramón Estruch drew 7,447 people from his five-year study and proved that the risk of stroke and heart disease of people on the Mediterranean diet is reduced by 28–30% compared to people on a low-fat diet.

Although the Mediterranean diet is more often used to prevent cardiovascular disease, it is also effective for weight loss, especially in the long run. This is confirmed by numerous studies.

A meta-analysis of randomized controlled trials showed that the Mediterranean diet can be a useful tool for weight loss, especially if you cut the calorie intake.

5. Diet Ornish

Diet OrnishThis is a low-fat diet devised by Dean Ornish, a professor of medicine at the University of California. It is aimed at improving heart health, getting rid of excess weight, lowering cholesterol and blood pressure. 

What is the essence of the diet?

The main rule of the Ornish diet is that fat should be no more than 10% of the total calorie intake. At the same time, it is advised to exclude meat and fish, butter and margarine, olives, avocados, seeds, nuts, fatty dairy products, sweets, alcohol.

Fat-free dairy products, egg whites, and low-fat crackers may be present in the diet. Without restrictions, you can consume legumes, fruits, cereals, vegetables.

In addition to the diet, Ornish advises to perform physical exercises (at least 30 minutes five days a week or 60 minutes three days a week), cope with stress through yoga and meditation, and spend time with loved ones.

What science says?

A study by Ornish published in the Journal of the American Medical Association in 1998 showed that people on his diet lost 10 kg in a year, and five years later maintained a weight that was 5 kg different from the original.

In the Stanford University study mentioned above, people on the Ornish diet lost an average of 2.2 kg per year. However, Dr. Michael L. Dansinger in 2005 received other results. During the year, test subjects on the Ornish diet lost 3.3–7.3 kg, while those on the Atkins diet lost 2.1–4.8 kg.

As with the vegan diet, people on the Ornish diet may suffer from a lack of protein and vitamin B12. Therefore, it is worth taking this vitamin in supplements and often include legumes rich in vegetable protein in the diet.

What does it mean?

As you can see, all diets are very different. Atkins diet limits carbohydrates, Ornish — fats. Paleo diet focuses on meat, and vegan meat completely eliminates. Moreover, scientific studies confirm the benefits and effectiveness of all these diets. And this is just great!

Choose a diet that does not make you give up your favorite foods. You can’t live without meat, choose a paleo or Atkins diet. Love pasta, become a vegan or stick to a Mediterranean diet. If you can easily do without fatty foods, Ornis diet will help you lose weight.