Popular Weight-loss Diets and Their Health Risks

Dietitians recommend a balanced diet and regular exercise for long-term weight loss and overall wellness. However, popular diet trends continue to gain popularity with people who want to lose weight—despite health risks and unknown long-term effects. 

According to Samantha Turnage, registered dietitian at Baptist Memorial Hospital-Desoto, diets that restrict or limit certain foods or food groups can result in weight loss. However, these diets also can pose health dangers. So, it’s important to understand the health risks associated with these popular diets before starting a weight loss regimen.

1. The Raw Food Diet

With the raw food diet, people do not eat food cooked above 116 degrees, including meat. Followers of the raw food diet believe eating uncooked or undercooked food preserves vitamins, phytonutrients and enzymes. This diet focuses on raw, easily consumed low-calorie foods, such as vegetables and fruits.

However, some uncooked food poses serious health risks, especially meat and dairy products.

“Unpasteurized dairy commonly transmits Listeria [a bacterial infection caused by eating contaminated food], which is detrimental to pregnant women and leads to stillbirth,” said Turnage. “Raw meat consumption also increases your likelihood of ingesting dangerous bacteria called E. coli.”

At the same time, people who avoid meat risk nutrient deficiency. People following the raw food diet tend to avoid many nutrient-dense foods, such as cooked beans and grains. If you’re considering a raw food diet, Turnage advises following a modified version by incorporating some cooked foods.

“A variety of raw and cooked foods leads to a well-balanced and varied diet,” said Turnage. “However, pregnant women should avoid the raw food diet due to the increased health risks.”  

2. The Ketogenic Diet

Ketosis is the process where the body burns fat instead of glucose for energy. The ketogenic diet, or keto, consists of high-fat foods, meats with moderate protein and foods with little-to-no carbohydrates.

To attain the macronutrient distribution needed to obtain ketosis, people following a ketogenic diet consume only meat, fish, butter, eggs, cheese, heavy creams, oils, nuts, avocados and low-carbohydrate vegetables, such as broccoli and cauliflower.

“I would be wary of recommending the keto diet for weight loss because it’s a restrictive diet that limits fruits, vegetables and fiber-filled foods,” said Turnage.

Currently, the long-term health effects and sustainability of the keto diet remain largely unknown. If you’re following this diet, take a multivitamin and electrolyte mineral supplement to prevent nutrient deficiencies during ketosis.

3. The Paleo Diet

Also known as the “caveman” or “Stone Age” diet, the paleo diet promotes the eating style of hunter-gatherers living in the Paleolithic era. Followers of this diet consume fruits, vegetables, nuts, seeds, healthy oils (including olive, coconut and avocado oil), grass-fed meat, fish, poultry and cage-free eggs.

This diet excludes grains, dairy, legumes, potatoes, refined sugar and refined vegetable oils because these foods were developed after the agricultural revolution. Like the ketogenic diet, the paleo diet lacks sufficient research detailing long-term health effects.

“It’s an incorrect assertion that our ancestors were biologically similar and healthier than humans are today,” said Turnage. “Prehistoric humans lived shorter lives due to infectious disease and accidents. Most didn’t live long enough to develop chronic disease.”

According to Turnage, paleo’s restrictive nature, expensive foods and exclusion of certain food groups make it an ineffective method for long-term weight loss for many people.

4. Whole30

A stricter form of the paleo diet, Whole30 excludes all sugar, including real, artificial and natural. It promotes protein, vegetables, fruit, healthy fats and some carbohydrates. Whole30 followers avoid grains, dairy, alcohol and soy.

“Whole30 dieters eat three square meals a day and avoid snacking,” said Turnage. “It’s more restrictive than most diets. It doesn’t focus on weight loss and isn’t a long-term diet or lifestyle.”

Instead, Whole30 aims to improve energy levels and alleviate health issues related to diet within a 30-day period. This approach can help dieters adopt healthy lifestyle habits by focusing on their overall health and wellness. People who follow a Whole30 diet often experience changes in sleep, energy, skin and mood. However, avoiding sugar, processed foods, grains and dairy can result in short-term weight loss.

“Food restrictions and categorizations make Whole30 unfavorable for long-term weight loss,” said Turnage. “For a program that claims to help patch up botched relationships with food—categorizing foods as good and bad is not a great place to start.”

5. The Gluten-free Diet

A gluten-free diet restricts foods containing gluten, a binding protein found in most carbohydrates, including wheat, rye, barely and other grains.

“About a decade ago, most stores lacked gluten-free products, and people purchased gluten-free alternatives from specialty stores or online,” said Turnage. “Now, most stores and restaurants sell gluten-free foods. Food makers even use labels and packaging to promote gluten-free products as healthier alternatives.”   

The gluten-free diet gained popularity after receiving endorsements from celebrities and professional athletes who attributed the diet to weight loss and improved athletic performance.

“No scientific evidence supports these claims for the general population,” said Turnage. “Gluten-free foods don’t offer significant health benefits unless you’re diagnosed with Celiac disease or experience gluten sensitivity.”

If you prefer to follow a gluten-free diet, be aware of the nutrient deficiencies and risks involved in excluding a large category of food from your diet. Gluten-free foods made with refined flours and starches—such as cake, cookies, muffins, crackers, breads and pizza—tend to lack iron, fiber and B vitamins.

Healthy Habits for Long-term Weight Loss

While plenty of diets result in weight loss, maintaining it is difficult on a restrictive diet. According to Turnage, diets can cause you to disconnect from your body’s internal cues and instincts about food. Some diets can result in disordered or obsessive eating habits.

For long-term, sustainable weight loss, adopt healthy lifestyle changes and habits. Be mindful of what you eat, but don’t limit or restrict certain foods for the sake of following a diet.

“Dietitians have advised patients on sensible weight loss for years,” said Turnage. “Eat less and exercise more.”

Learn more about Baptist’s fitness programs on the Fitness and Wellness Programs page or about weight loss options on the Baptist Weight Loss Center page. Find a specialist by visiting our Find a Physician page.