5 Diets that Can Be Dangerous

By Lizzie Streit, MS, RDN, LD 

Fad diets are incredibly popular among those who are trying to lose weight and get healthy. These diets often promise quick fixes and dramatic results, but are difficult to sustain and ineffective in the long run.  

There are countless fad diets that exist in many forms. Some promote pills, juices, or powders as a substitute for real food. Others emphasize whole foods but also encourage restriction of entire food groups or macronutrients. Fad diets may promise weight loss, prevention or treatment of chronic diseases, or both.  

However, all fad diets have a common thread: they tend to come with a laundry list of rules. Avoid all dairy! Eat this but not that! Follow this plan for 28 days to be skinny forever! And the list goes on.  

In most cases, those who follow fad diets end up ditching the protocol before the end date. Some may see a diet through to the end only to find that they can no longer maintain the results when they return to their regular eating habits. 

But one serious consequence of fad diets is often overlooked. With their extreme rules, restrictions, or protocols, fad diets can at times be dangerous. In fact, some fad diets may lead to nutrient deficiencies and related health issues over time.  

Here is a list of popular fad diets and their shortcomings.  

  1. Paleo and Whole30 

The paleolithic (paleo) diet, and its closely related sister diet Whole30, encourage eating mostly whole, unprocessed foods and eliminating added sugars, dairy, grains, most legumes, and alcohol.  

The paleo diet is based on the premise that foods cultivated by modern farming techniques are the culprits of underlying food intolerances and poor health. Proponents of the diet believe that eating foods such as dairy, grains, and beans contribute to obesity, chronic disease, and other modern-day health issues. To avoid health problems, the paleo diet suggests restricting these foods and focusing on vegetables, fruits, nuts and seeds, healthy fats, and lean meats and fish.  

While Whole30 is based on the principles of the paleo diet, it is more of a monthly reset than a long-term diet. Whole30 recommends eating only paleo foods for 30 days, then slowly re-introducing the eliminated foods while monitoring how your body reacts to them. It is claimed that this process can help you identify the types of foods you can tolerate, as well as the foods you should avoid. 

Cons: Paleo eliminates beans and whole grains, both of which are excellent sources of fiber, vitamins, and minerals. Not consuming dairy may also lead to inadequate calcium and vitamin D intake, especially if you do not eat enough plant-based sources of calcium. Due to the number of restrictions, it can also be difficult to stick to paleo eating in the long term.  

Pros: A paleo diet is based on nutritious whole foods. Testimonials and limited research suggest that this style of eating may help with weight loss and blood sugar control.  

2. Ketogenic Diet 

The ketogenic, or keto, diet is hugely popular and touted as one of the most effective ways to lose weight. This diet originated as a way to help individuals with epilepsy manage their seizures, but has since been adopted by thousands of people who want to slim down. 

The diet recommends getting the majority of daily calories from fat (~70%), a moderate amount from protein (~25%), and a very low amount from carbohydrates (~5%, usually less than 30 grams per day on a 2,000 calorie diet). This style of eating is thought to put your body into ketosis, a fasting state during which the body burns fat for energy.  

A typical keto diet focuses on foods such as meat, fish, high-fat dairy, avocados, fatty fish, nuts and seeds, and low-carb vegetables (leafy greens, peppers, broccoli, onions, etc.). 

Cons: There is limited research on the long-term effects of ketogenic diets. The diet encourages extreme carbohydrate restriction and therefore a low intake of fruits, vegetables, whole grains, and beans, making it difficult to follow the diet for extended periods of time. In addition, not getting enough of these foods, or not eating enough variety of low-carb vegetables, may lead to an inadequate intake of fiber, vitamins, and minerals.  

Pros: Weight loss may happen rapidly, but mostly as a result of losing water weight and decreasing calorie intake. Most people who follow a keto diet report feeling satisfied after meals. Finally, the body of research that highlights the benefits of the ketogenic diet for a variety of conditions, including blood sugar control, continues to grow. 

3. Juice Cleanses 

Juice cleanses exist in many forms, but all of them encourage drinking juice from fruits and vegetables while avoiding all or most other foods for a period of 3 to 10 days.  

The idea behind juice cleanses is that they “detox” the body, decrease inflammation, and promote energy. During a cleanse, people may use juices from a specific company or make their own juices.  

It’s important to note that juicing is different than blending. Juicing involves squeezing out juice from fruits and vegetables and discarding the pulp and fiber, whereas blending maintains the pulp and fiber.   

Cons: There are several dangers associated with juice cleanses. They do not provide adequate calories and can lead to fatigue, weakness, hunger, headaches, and possibly low blood sugar. Drinking excessive amounts of juice may also be associated with kidney stones in people with kidney issues. If juices contain laxatives or digestive agents, drinking large quantities of them may result in losing too many nutrients in stool. Lastly, unpasteurized juices that do not have bacteria removed may put some populations, such as the elderly and pregnant women, at a greater risk of developing infections or illnesses. 

Pros: Anecdotal evidence suggests that juice cleanses help kickstart the immune system, flush toxins from the body, and improve digestion. However, there is no research to back these dramatic claim 

4. Alkaline Diet 

The alkaline diet suggests that eating foods that do not disrupt the body’s pH levels promotes health and may prevent disease.  

According to proponents of the diet, alkaline-rich foods include fruits, vegetables, nuts and seeds, and legumes. Meats, dairy, fish, eggs, grains, and alcohol are considered acidic foods. It is claimed that diets primarily made of alkaline foods help maintain an optimal body pH.  

Cons: The body already regulates its internal pH, and there is no research to back the idea that foods can impact pH. The restriction of certain foods encourages fear around eating and may make it difficult to get all of the necessary nutrients. Plus, whether a food is alkaline or acidic is not listed on food labels, making it challenging to find the right foods to eat. 

Pros: The alkaline diet is mostly plant-based and composed of nutritious, whole foods. It encourages avoiding highly processed foods that are loaded with salt, unhealthy fats, and sugar. 

5. Raw Veganism  

A raw vegan diet is an extreme form of plant-based eating that avoids any foods that have been cooked or processed. Proponents of the diet suggest that cooking foods destroy enzymes and other nutrients that promote digestion and optimal health. 

The diet is based on fruits, vegetables, nuts and seeds, and other plant foods in a “raw” state. Appropriate preparation techniques include juicing, blending, cutting/chopping, sprouting, and dehydrating.  

Cons: There is considerable time and effort involved in preparing foods that fit a raw vegan diet. The diet’s restrictions also make it incredibly difficult to get all of the necessary nutrients, which may lead to low energy and deficiencies. 

Pros: A raw diet is high in fiber and does not include any highly processed foods with added sugars, chemicals, salt, or preservatives. 

Even though fad diets come in many different forms, they are all difficult to maintain and may even put your health in danger. Consuming a varied diet based on vegetables, fruits, beans, nuts and seeds, whole grains, lean proteins, and dairy will provide all of the necessary nutrients. A balanced diet with real, whole foods can also promote weight loss and keep you feeling healthy and happy. 

Note From Healthy For Life Meals: Instead of following the latest fad diet or eating trend, opt for a meal plan that’s based on decades of science!  Our meal plans follow guidelines set by the most respected health and nutrition experts, and focuses on fresh, clean, whole foods.  Our menu includes a variety of nutrient-dense ingredients from all the food groups, without crazy rules and restrictions!  Check out our menu today.  

Stef Keegan