13 Restrictive Diets You Should Think Twice About Trying

Extreme Diets and Their Pitfalls


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Extreme Diets and Their Pitfalls


When it comes to diet, there is no one catch-all solution. These days, there are so many fads and extreme diets, some of which may work well for some people and not at all for others. The first and most important step is to understand as much as you can about yourself and your unique circumstances and abilities, then make a plan that suits you. If you are considering a radical diet, it's important to understand what the diet is, how it functions, and what its risks are in order to make an informed choice about a lifestyle or temporary diet that works for you.

Worst: Ketogenic Diet


Often referred to as "keto," this diet is popular among people who want a quick weight-loss solution. By avoiding easily digested carbs like grains, sweeteners, and fruits, your body switches the way it makes energy, going into a state of ketosis, which then burns fat for energy. This high-fat diet may not work for everyone, especially those concerned about cholesterol or those who already have a low percentage of body fat.

Sugar Detox


This diet provides four hard-and-fast rules, or bright lines, to follow when it comes to eating habits. Basically, the diet cuts out all forms of sugar, even dried fruit; it eliminates flours of any kind, even flours from non-grains like almond or coconut flour; it also means eating only during meal times, and requires strict portion control. While the Bright Line Diet produces results for most people who try it, the strict rules conflict with many people's lifestyles, and can be socially prohibitive.



People decide to go vegan, which is a total elimination of all animal products, for a variety of reasons from ethical concerns to health issues. By eliminating all meat and dairy, some people increase their intake of plant-based food, which can lead to a healthier life. There are plenty of downfalls with a vegan diet though, like eating overly processed meat and dairy substitutes, and experiencing nutrient deficiencies that require vitamin supplementation.

Gluten Free


The protein that makes breads and doughs stretchy is gluten, which has also been linked to a number of health issues, even if you are not 100 percent intolerant or have celiac disease. By eliminating gluten, many people report higher levels of energy, less stress, and better functioning gastrointestinal functions. Going on a gluten-free diet temporarily may cause longer-lasting gluten intolerance, which means it could end up being permanent even when not intended.

High Protein
Thomas Francois/istockphoto


Increasing protein, while keeping carbs low, has been linked to weight loss and some other health benefits like increased energy. Protein is not converted into fat as easily as carbs or fat, and when paired with an active lifestyle, can be turned into an efficient energy source. While on a high-protein diet, it is easy to omit fiber in general, leading to constipation and other digestive issues.

Raw Foods


Eating only raw fruits, vegetables, and legumes can be done as a cleanse, or as a lifestyle. While a temporary raw food diet is low-risk for most people, it can be inflammatory for some people's digestive systems, especially when taken on as a lifestyle. Eating raw foods can also mean having to spend a lot of time on preparing and eating food since more is required to get the needed calories.

Fruit Only


There's no question that fruit is healthy, but only fruit? Fruit is often high in sugar, which can cause complications for those who have issues with blood sugar. The lack of protein or fat is also a major issue for long-term health. Beyond a day or two, an all fruit diet seems unsustainable and lacking in nutrition.

Calorie Restriction


A diet that limits calories to a minimum, or even below the recommended minimum, has been linked to maintaining youthful appearance and overall health. For many, the calorie-restricted lifestyle is too difficult or not enjoyable enough for people to take it on. Imagine eating a few ounces of spinach and an ounce of chicken for dinner, and a few ounces of red wine per week. Is that the kind of life you want to stay young for?

Intermittent Fasting


Fasting for a portion of the day can shift the way your body metabolizes food, leading to weight loss, more energy, and other benefits. Most people recommend skipping dinner, but skipping breakfast is also an option, in other words, eating just two meals per day. While is can work, intermittent fasting can also lead to weight gain and instability in digestion when not done correctly.



Paleo is all about going back to basics, or how the Paleolithic humans ate, before agriculture. The Paleo Diet cuts out grains and most refined foods, which can aid in weight loss. It can be difficult to follow the paleo rules in many social contexts, and also may lead to eating highly processed foods, like coconut flour, which is technically inside the parameters, but also very far from what our ancestors were eating.

Grain Free


Grains are coming under fire from health experts all over the globe as the possible culprits for allergies and health issues in modern society. Many of the grains we eat today have been cultivated and tweaked by man for centuries and are not as nutritious as their heirloom ancestors. Cutting out all grains can lead to vitamin deficiencies in some people, and also a lack of enjoyment of food without any guarantee of improved health or weight loss.

Low or No Fat Eating


There was a time that people were taught that fat was unhealthy and should be kept to a minimum at all costs. In reality, fat is an essential nutrient that we need, and is especially good to maintain healthy brain function. Cutting out all natural fats can lead to serious deficiencies, bad moods, and depression, not to mention a lack of flavor in food. Of course it's wise to choose healthy fats versus unhealthy fats, but cutting out or down on fat rarely leads to better health or weight loss.



Juicing has become a popular fad for people of all ages across the world. Juice is a quick and easy way to pack a lot of nutrients into your day, but it also removes the fiber from the fruits and vegetables, which is vital for a healthy digestive system. Going on a juice diet, even for a few days, can cause damage to your gastrointestinal system as well as imbalances of blood sugar from consuming the sugar of fruits and veggies without their fiber.