Plant-Based, Keto, Whole30: What All Those Trendy Diets Mean

Many fad diets have come and gone through the years. Some are effective guidelines that help people manage their weight or address health concerns. And others have been renounced as unhealthy or even dangerous by professionals once they hit the mainstream. These 20 trendy diets are currently all the rage, but what do they entail? And more importantly, are they safe and effective? Here's the scoop on keto, Whole30, the Mediterranean diet and more.

Rather than a traditional diet, Intermittent fasting (IF) is more of an eating pattern that regulates periods of fasting and eating in order to lose weight. There are multiple IF schedules people can prescribe to. One of the more popular dictates daily 16-hour fasts with eating restricted to eight hours during the day, such as noon to 8 p.m. Another method is called 5:2 and requires fasting two days out of the week with very little calorie intake on fast days. Though intermittent fasting is more restrictive in nature and doesn't work for people with certain health issues like diabetes, early studies indicate that it can be effective for weight loss and can cause less loss of muscle mass than calorie-restrictive diets.

"Plant-based" is a newer diet term that refers to eating minimally processed ("whole") foods mostly or entirely derived from plants. This means limited dairy and meat consumption and no refined foods like white flour or added sugar. Instead, your diet consists of vegetables, fruits, whole grains, legumes, seeds and nuts. While it is similar to vegan and vegetarian diets, it does allow some animal products. Studies have shown healthy plant-based diets can lower your risk for heart disease. According to the American Heart Association, eating less meat can also reduce the risk of stroke, high blood pressure, high cholesterol, certain cancers and obesity.

One of the biggest food trends of the 2010s was the emergence of the keto diet, which is short for ketogenic. The goal of this diet is to put your body into a metabolic state called ketosis by drastically reducing your carbohydrate intake and replacing it with fat. Once in ketosis, your body will burn fat rather than glucose for energy, leading to weight loss. On the keto diet, you cannot consume any grains, sugar, beans, legumes or most fruit, instead focusing on meat, eggs, dairy and green vegetables. Studies have shown the keto diet can be effective for weight loss as well as managing glucose levels for those with type 2 diabetes or prediabetes. It does have some drawbacks, however, including potential digestive issues and fatigue known as the "keto flu."

Developed in 2009 by two certified sports nutritionists, the Whole30 diet encourages followers to only eat "whole" or minimally processed foods for 30 days. This means no alcohol, sugar, grains, legumes, dairy or additives. After the 30 days, you can slowly introduce eliminated foods back into your diet. The goal of the diet is to help reset your eating habits and metabolism, though many also adopt it to try to lose weight. 

Paleo is short for Paleolithic diet because it's based around the foods that would've been available to humans during the Paleolithic era, which was about 10,000 to 2 million years ago. That means no beans. potatoes, processed foods, dairy, refined sugar, grains, refined vegetable oils or salt. There was no farming, ranching or domesticated animals yet, so the only meat you can have is grass-fed meat, fish and seafood. The paleo diet does include eggs, nuts, fresh vegetables and fruit and nuts and seeds. Clinical trials have suggested the diet could help with weight loss and controlling blood pressure, but many of its health benefits are still unproven, according to the Mayo Clinic.

The "pegan" diet combines the restrictions of the paleo diet with a vegan diet, which doesn't include any meat or animal products. However, the pegan diet, developed by Dr. Mark Hyman, does allow small to moderate amounts of meat and certain fish, making it a bit more flexible than a paleo or vegan diet on its own. However, 75% of intake on this diet is supposed to be vegetables and fruit.

This trendy portmanteau name is simply a combination of "flexible" and "vegetarian." Flexitarian has arisen as a more approachable diet option for those unable to go fully vegetarian or vegan. Flexitarians will occasionally enjoy a meat dish but the bulk of their diet will be based on vegetables, fruits, whole grains, nuts and seeds. There is an official "Flexitarian Diet" book and recipes that can help you feel full on fewer calories. Or you can simply commit to diet and lifestyle changes involving more exercise and eating more fruits and vegetables that can benefit your overall health. The "flexible" part of Flexitarian means this diet can be built for you.

The Mediterranean diet is based on the foods eaten in countries like Italy and Greece, which border the Mediterranean Sea. This balanced diet focuses on fruits and vegetables, whole grains, beans and seeds with a big emphasis on extra virgin olive oil. Consumption of meat, refined sugar and flour are reduced compared to traditional Western diets. This diet is promoted by reputable organizations as a way to lose weight and prevent chronic health issues like cardiovascular disease. The Mediterranean diet is recommended by the Dietary Guidelines for Americans and the World Health Organization and was named the best diet of 2019 by U.S. News and World Report.

DASH is an acronym that stands for Dietary Approaches to Stop Hypertension, and this diet is promoted by the National Heart, Lung, and Blood Institute. DASH reduces hypertension, also known as high blood pressure, by boosting your intake of nutrients like potassium, calcium, protein and fiber and reducing sodium intake. To achieve this, the diet encourages changes like adding one serving of fruits or vegetables per meal, switching from white to whole wheat flour and making two or more meals each week meat-free.

Another acronym diet, MIND stands for Mediterranean-DASH Intervention for Neurodegenerative Delay. As its name suggests, MIND combines aspects of both the Mediterranean and DASH diets in order to prevent dementia and loss of brain function as you age. This diet doesn't have specific recipes or a program but calls for a reduction in five foods: butter and margarine, cheese, red meat, fried foods, and pastries and sweets. Instead, it recommends consuming more vegetables, berries, beans, whole grains, olive oil, fish, poultry and wine.

The Snake diet takes fasting to an extreme level by recommending fasting for up to three days at a time. During that period, you're only supposed to drink a concoction called "snake juice" made of water, salt, potassium chloride, baking soda and magnesium sulfate salts. While this diet will likely lead to weight loss due to lack of eating, it will harm your immune system, metabolism and other normal bodily functions, according to the experts. It could also lead to disordered eating patterns and relationships with food and is not recommended by health professionals. 

Despite objections from health professionals, juice cleanses and juicing are still popular diet trends. In a juice cleanse, people typically only drink fruit and vegetable juices for three to 10 days. Removing solids from your diet negatively impacts digestion and can actually slow down your metabolism. Juice cleanses can provide short-term results but they're not a healthy long-term solution for weight loss or overall wellness.

Developed by the medical nonprofit the Mayo Clinic, this diet is based on the clinic's recommended food pyramid as well as healthy lifestyle advice, like being engaged in physical activity for at least 30 minutes a day. The diet emphasizes vegetables, fruits and whole grains, while reducing consumption of fats and sweets. Buying the book or joining Mayo Clinic's online program is the only way to access all the diet's restrictions, recipes and tools.

The raw diet lives up to its name by including fruits, vegetables and grains that have not been cooked or heated over 104–118 degrees F. They should also not be processed, refined, pasteurized or treated with pesticides. Instead, food can be prepared by juicing, blending, soaking, dehydrating and other methods. The idea behind this diet is that cooking food destroys its nutrients, which is not based in science. Strictly following this diet would also be deficient in many necessary nutrients.

Perhaps instead of being more healthy like someone from the Mediterranean, you want to take your cues from farther north. The Nordic diet is based around foods commonly eaten by people in Nordic countries (Denmark, Finland, Iceland, Norway and Sweden). It emphasizes high-quality meat and organic, local produce as well as paying attention to your carb-protein ratio in meals. The diet was developed by nutritional scientists based at Denmark's University of Copenhagen and one of the co-founders of the famous Danish restaurant Noma.

Plenty of low-carb fad diets such as Atkins, South Beach and keto have cropped up over the years, but the modern extreme version of these plans is the "no-carb" or "zero-carb" diet. Someone on a no-carb diet must eat foods that contain primarily protein or fat, such as meat, fish, eggs, cheese, oils and butter while cutting out breads, grains, starchy vegetables and fruit, milk, beans, nuts and seeds. While reducing your carb intake can result in weight loss, completely eliminating carbs from your diet is unnecessary for losing weight, maintaining a healthy weight and preventing diseases and could remove vital nutrients from your diet.

A diet dating back to the 1960s that's had a recent resurgence, the macrobiotic diet focuses on natural, organic food and eliminating chemicals and artificial ingredients in order to put you in harmony with the world around you. The macrobiotic diet is largely plant-based, low-fat and high-fiber, which can help lower the risk of heart disease and some kinds of cancer. More intense practitioners of this diet cook without microwave ovens or electricity and eliminate plastic from their kitchens, but less zealous people can still reap some potential health benefits from this diet.

As suggested by its name, the Volumetrics diet is based on the volume. It was developed by Dr. Barbara Rolls, a professor of nutrition and head of nutritional sciences at Pennsylvania State University, and is backed up by research and studies. The idea behind it is that "energy-dense" foods will help you feel more full while eating less. Foods are split into four categories, with Category 1's "anytime" foods including non-starchy fruits and vegetables like broccoli and tomatoes, nonfat milk and broth-based soup. Category 2 is reasonable portion foods including lean proteins, whole grains and legumes. Category 3 is small portion foods like bread and cheese and Category 4 is food to be eaten sparingly like sweets and fried foods. The diet has an official book with recipes, but Volumetrics is also a helpful philosophy that can be applied less strictly. ​​​​​​

Created in 1977 by Dr. Dean Ornish, the Ornish diet is low in fat, refined carbohydrates and animal protein. Like the Volumetrics diet, it groups foods into five categories, but it also emphasizes exercise, stress management and social support and integral aspects of health and happiness. Though the diet is low in healthy fats, it has been shown in studies to improve heart health and help reverse heart disease. In fact, Medicare and many private health insurance plans cover Dr. Dean Ornish's Program for Reversing Heart Disease, an intensive lifestyle intervention program for patients with heart disease.

The anti-inflammatory diet is fairly straightforward in that its goal is to eliminate foods that trigger inflammation in the body and add in more foods that have anti-inflammatory effects. People on this diet avoid red meat, fried foods, white bread and more while eating more green leafy vegetables, tomatoes, fruits, nuts and fatty fish. Combating inflammation can help reduce the risk of many chronic illnesses such as arthritis, cancer, heart disease and diabetes. Eating less inflammatory foods is just one of the healthy diet changes you should make after age 50.

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