Pros and Cons of 10 Different Weight Loss Diets

According to Statista, 80% of adults under the age of 36 admit that they “could be healthier.” Better health is a concern for Americans, especially since the United States has the highest obesity rates among OECD countries.

Food Insight found that one-third of U.S. consumers reported following a diet in 2018, up from 14% in 2017. There are a wide variety of diets, both restrictive and nonrestrictive, available to U.S. consumers.

Before choosing a diet, you should speak with your healthcare provider to discuss each diet's potential benefits and drawbacks. In some cases, a diet may not be appropriate for your lifestyle.

1. Paleo Diet

The paleo diet is named after the Paleolithic era and focuses on foods that humans would have eaten over 10,000 years ago. Those following a paleo diet focus on eating lean meats, fish, fruits, vegetables, nuts, and seeds, while avoiding grains, dairy, and legumes.

Pros of the Paleo Diet

Some studies have shown that the paleo diet improves glucose tolerance and decreases the risk for diabetes. In another study, individuals followed the paleo diet for three weeks and lost an average of five pounds (although this study had no control group).

Cons of the Paleo Diet

The paleo diet excludes many healthy grains and legumes, which could limit the amount of fiber and other nutrients that individuals eat in a day.

Athletes need between three and 12 grams of carbohydrates per pound of body weight per day to sustain high activity. Those following the paleo diet may struggle to reach their carbohydrate needs.

2. Keto Diet

The ketogenic diet focuses on low carb and high fat intake to force the body into a metabolic state referred to as ketosis. Some studies show that the diet can help individuals lose weight and prevent diabetes and cancer.

Those following the diet will avoid eating:

Processed sugar;
Grains and starches;
Root vegetables;
Beans and legumes;
Fruit.

Those following the keto diet have diets that are high in meat and low in sugar.

Pros of the Keto Diet

The diet feels less restrictive because it discourages low-fat foods and instead encourages people to focus on high-fat foods. The diet may help obese individuals lose weight and may have positive effects on neurological disorders.

Cons of the Keto Diet

There is limited information available on the long-term effects of ketosis, making the diet concerning for those who plan to make it a lifestyle instead of a short-term diet. Additionally, because the diet eliminates fruits, legumes, some vegetables, and whole grains, it could lead to deficiencies in certain vitamins and minerals.

3. Vegan Diet

The vegan diet is a plant-based diet that eliminates animal products entirely and focuses on eating fruits, vegetables, whole grains, legumes, nuts, and seeds.

Pros of the Vegan Diet

A study conducted in 2013 states that physicians should consider recommending plant-based diets to patients to lower body mass index, blood pressure, and cholesterol levels. Following a vegan diet may also “reduce the number of medications needed to treat chronic diseases and lower ischemic heart disease mortality rates.”

Cons of the Vegan Diet

Plant-based diets are restrictive and require meal planning. An individual who follows a long-term plant-based diet and fails to properly plan their meals may end up with B12, iron, and omega-3 fatty acids deficiencies.

4. HCG Diet

The HCG diet includes regular injections of human chorionic gonadotropin (HCG) along with calorie restrictions. Those following the diet only eat 500 calories per day, and the HCG injections prevent the dieters from feeling hungry during the severe calorie restriction.

Pros of the HCG Diet

Those following the HCG diet can lose one to two pounds a day while using daily injections of HCG that prevent hunger, tiredness, or weakness. HCG may help individuals reset their metabolism and burn fat quickly.

Cons of the HCG Diet

HCG shots should only be purchased from trusted HCG sources. Exercising while on this diet may lead to lightheadedness. Additionally, due to the extreme calorie restriction and use of HCG, the diet is not recommended by the U.S. Food and Drug Administration (FDA).

5. Mediterranean Diet

The Mediterranean diet focuses on eating fruits, vegetables, nuts, seeds, fish, seafood, olive oil, whole grains, and starches. Those following this diet avoid red meat, processed meat, and refined foods.

Pros of the Mediterranean Diet

For most individuals, the Mediterranean diet can easily become a lifestyle because many healthy, unprocessed foods are encouraged without restriction. Some studies suggest that following the diet reduces the risk of metabolic syndromes, diabetes, cancer, and neurodegenerative diseases.

Cons of the Mediterranean Diet

The diet is designed to promote overall health and isn’t for those specifically looking to lose weight.

6. Atkins Diet

The Atkins diet is a popular low-carb diet for those looking to lose weight. Those following the diet eat meat, fish, eggs, low-carb vegetables, healthy fats, and full-fat dairy products, while avoiding carbs and sugar.

Pros of the Atkins Diet

The Atkins diet is similar to keto by promoting a state of ketosis and may improve cognition in older adults. The diet may also promote weight loss.

Cons of the Atkins Diet

Due to the restrictive nature of the Atkins diet, it can be hard to maintain for long periods. Additionally, the diet doesn’t recommend fruit, which could lead to low fiber intake or deficiencies in certain vitamins. Some individuals may experience ill effects from ketosis.

7. The Zone Diet

The Zone diet encourages individuals to eat specific ratios of macronutrients: 40% carbs, 30% protein, and 30% fats. The diet aims to prevent inflammation in the body and encourages weight loss.

Pros of the Zone Diet

According to Dr. Sears, the Zone diet reduces inflammation, decreases the risk of diabetes, and promotes weight loss. By reducing inflammation, Dr. Sears states that the body will be more resistant to gaining weight, sickness, or aging.

Cons of the Zone Diet

Some studies report that there is little scientific backing to the claims made by the Zone diet.

8. Intermittent Fasting Diet

The intermittent fasting diet combines periods of eating and periods of fasting. One example of intermittent fasting is the 16/8 method, where individuals fast for 16 consecutive hours and then have an eating window of eight hours.

Pros of Intermittent Fasting

A study published by the New England Journal of Medicine found that fasting for 18 hours and eating in a six-hour period may increase an individual’s stress resistance, increase their lifespan, and decrease the risk of disease.

Cons of Intermittent Fasting

Intermittent fasting doesn’t always promote weight loss, according to a study published in JAMA.

9. Lipo Diet

The lipo diet focuses on avoiding carbohydrates, fruit, and sugar. The diet also encourages lipo injections which can burn fat and increase your metabolism. Some people compare the lipo diet to the HCG diet because both require injections.

Pros of the Lipo Diet

A lipo diet plan is less restrictive than the HCG diet and allows for 1,200 calories for women and 1,500 calories for men. The injections can also help individuals increase their metabolism and burn fat faster during exercise.

Cons of the Lipo Diet

The lipo diet is not encouraged for long-term weight loss because the long-term effects of lipo injections have not been thoroughly studied.

10. Carnivore Diet

The carnivore diet only focuses on meat and animal products. The diet eliminates carbs and focuses solely on protein and fat. Diet extremists consume only meat and water.

Pros of the Carnivore Diet

There is no scientific evidence backing the benefits of the carnivore diet. Those on the carnivore diet claim to see fewer digestive problems and higher testosterone.

Cons of the Carnivore Diet

Ample studies are reporting negative health effects of eating too much meat, including:

The carnivore diet can also lead to severe nutrient deficiencies and is not recommended for individuals.