The intermittent fasting diet caught everyone’s attention recently when Jennifer Aniston revealed that she does it. There are different versions of this diet, which involves periods of going without solid food—Aniston favors the 16:8 version, which means she eats within an 8-hour window then fasts for 16 hours. But does it actually work? It can. 

“It’s suspected that the reason it helps people lose weight is that eating within an 8-hour window simply limits the total amount of calories consumed in a day,” New York-based nutritionist Lauren Harris-Pincus, RD, previously told Health.

The Dr. Sebi diet is a controversial one. The guy behind it is the late Alfredo Darrington Bowman, aka Dr. Sebi, who wasn’t a medical doctor but a self-educated herbalist. It didn’t help that he claimed (until a 1993 lawsuit ordered him to stop doing so) that his diet could cure conditions like AIDS, sickle cell anemia, lupus, and leukemia. Basically, the Dr. Sebi diet promotes consuming plant-based foods and supplements that supposedly decrease disease-causing mucus by bringing the body into an alkaline state.

“Noom diet” was one of the top trending diet searches in 2018, and it’s high on the list again this year. Noom is actually an app—one that lets users log meals, access workout plans, track exercise, set goals, rate their motivation level, and connect with like-minded people. It also has articles, recipes, and support from personal health coaches (although not RDNs). 

If that’s not enough, if attempts to address emotional eating and looks at how factors like stress and boredom can affect eating decisions. That all comes at a price, however: around $50 a month, and the plan is designed to last for four months. “While the app provides support, the user ultimately has to make his or her own eating and exercise decisions,” Cynthia Sass, MPH, RD, Health contributing nutrition editor, previously told Health.

Just as the name of this diet implies, it's an eating plan that limits dieters to 1200 calories daily. Many variations exist, and the diet doesn't restrict any one food group or type of food. While sticking to 1200 calories a day might sound feasible for the short-term, keep in mind that the USDA's Dietary Guidelines for Americans advises that moderately active women between ages 26 and 50 should take in about 2,000 calories daily to maintain a healthy weight. Cutting back to 1200 might be too restrictive to sustain.

The high-fat, low-carb keto diet was at the top of last year's top trending diets list from Google. Quick refresher: the goal of the diet is to get your body to a state of ketosis, where you burn fat for energy rather than carbs, which leads to weight loss. This variation of the super popular keto diet is basically keto with supplements, which claim to put your body in a state of ketosis or increase fat burning while you're in ketosis already.

The premise of the GOLO diet is that hormone imbalances lead to stress and anxiety, and this in turn makes you hungry and tired...which triggers overeating. While diet and exercise are part of the GOLO plan, users are also advised to take a supplement called Release to help bolster those healthy habits and boost weight loss. "Without independent data on Release, it’s difficult to say if it indeed leads to better results, and if it’s safe for all," Sass previously told Health.

Created by Heather Dubrow of Real Housewives of Orange County and husband Terry Dubrow, MD, one of the stars on Botched, the Dubrow diet is an intermittent fasting plan with three phases that focuses on whole foods and restricting calories. The diet features sample meal plans and it doesn't eliminate carbs. But all the phases and fasting windows could make it a bit complicated to follow, Sass previously told Health.

The Sirtfood diet can be filed under “Is this too good to be true?” It claims to be the only eating plan which actively encourages red wine and dark chocolate, which are both high in sirtuin activators. (Sirtuins are a type of protein that protects the body’s cells from dying and from inflammation, and research suggests they can help regulate metabolism, increase muscle, and burn fat.) This diet has actually been making headlines for a while due to (unsubstantiated) claims that singer Adele followed it to lose weight.

This plan appears to come from Jennifer Lopez and Alex Rodriguez, who announced on Instagram back in January that they would be attempting a 10-day no carb, no sugar challenge. Apparently J. Lo discovered that cutting out an entire macronutrient was not easy and reported this on social media: "So it turns out, when you don't have sugar and you don't have carbs, you're really really hungry all the time. So we're trying to figure out a lot of good snacks." 

This diet is inspired by research from the 1940s, when a psychologist classified people into three body types: ectomorphs, mesomorphs, and endomorphs, the latter having excess fat and less muscle tone. Supposedly, endomorphs have slower metabolisms, and their bodies are more likely to convert excess calories to fat. They're advised to eat more protein and fats while keeping an eye on carb intake.

If Google's 2019 list has inspired you to try any of these diets, just remember that most diets don’t work, insofar as they don’t lead to sustained weight loss. The worst case scenario is that a structured eating plan (no matter how “healthy” it claims to be) can lead to disordered eating habits.

If you think you need to lose weight, or simply want to eat more healthy foods, start by speaking to a doctor or nutritionist. “Many people have successfully lost weight and kept it off by simply consuming more whole food-based, balanced meals, eating mindfully, garnering support, and being active,” Sass said.

Types Of Diets: Weight Loss Plans From Low-Carb, To Low-Fat

A diet should be based on your medical situation and your goals, not simply the latest fad. Most importantly, it should be chosen to match the reason you want or need to follow a diet in the first place.

General Diet Categories

Some diets are medically indicated. Lactose-free diets are specific to those who are lactose-intolerant, for example, and restricted-fiber diets are designed for those who suffer from IBD or other gastrointestinal diseases.

Many standard diet plans are versions of the time-honored calorie counting approach, and are likely to be associated with well-known companies like Weight Watchers (now known as WW).

Other eating plans are based on philosophical approaches, or they’ve been created because the types of allowed or forbidden foods are either beneficial or detrimental to overall health. Vegan and “caveman” diets would fall into this category.

Then there are diets based on nutritional theories and real (or purported) results. These are the ones that most ordinary dieters opt for when they decide it’s time to fit into those old clothes (or buy some new, more stylish ones). The majority of these diets are based on a belief that limiting carbs (or fat, or refined sugars, or some other category of nutrients or ingredients) is the secret to weight loss. The Atkins diet, which has been around for decades, is a good example.

Many doctors suggest simply using common sense when eating, in order to achieve sustainable weight loss. Limiting portion sizes, eating whole foods instead of processed foods heavy in sugar, and eating smaller meals multiple times a day are among the elements of common-sense dieting. (5)

Finally, there are the fad diets usually chosen by those who simply want to lose weight in a hurry. As you likely know, most of these don’t work for any length of time, even though some folks certainly swear by them.

Don’t worry, we’re not going through all 100+ of the diets you can choose from. What follows, though, is a categorization of the different types of diets – along with a look at the most popular eating plan in each category.

One note before we start: Some of these diets could easily have been placed into more than one category. It’s not meant to suggest, for instance, that the Mayo Clinic diet isn’t based on sound nutritional theory; it simply conforms to the “common sense” approach to eating that we’ve all heard from our parents, teachers and doctors since we were young. Please use the category titles as starting points, rather than definitive labels.

Popular Diets Based on Nutritional Theories

Low-Fat Diet

This approach was popularized 40 years ago with the “Pritikin Program.” Any low fat-diet is based around food choices which are low in total fat, low in “bad” fats, and low in cholesterol. It will also suggest consuming 20-30 grams of fiber per day, primarily through the use of whole grains instead of wheat ones, and eating lots of fruits and vegetables.

These diets are still quite popular for weight loss, because the basic idea behind them is sound: fat contains more than double the calories of carbs or protein. However, many people simply substitute commercial “low-fat” versions of foods – including junk foods – and end up consuming way too much sugar and trans fats, defeating the effectiveness restricting fat. The low-fat diet can work, but only if it’s accompanied with smart eating and healthy, fresh ingredients.

Ketogenic Diet

The opposite of a low-fat diet is a low-carbohydrate diet, and the “Keto Diet” is the most popular of all low-carb diets. Why is it “the opposite?” Because Keto is deliberately a high-fat diet, which may seem counterintuitive but actually makes sense. The goal is to replace carbohydrates with fats; that keeps carb intake so low (no more than 25 grams per day) that the body enters a metabolic state that’s called ketosis.

When the body isn’t getting lots of new fat, it begins running primarily on stored fat. That’s the reason why Keto is so effective for fat burning and weight loss. (That’s also somewhat of a simplification, but it serves our purposes for now.) This diet is heavy on meat, fish, eggs, cheese and natural fats, but means giving up most bread, fruit, sweetened drinks and packaged/fast foods. As you could guess, it’s not the easiest program to follow, but it’s effective – not only for weight loss, but for control of blood sugar and triglycerides.

Atkins Diet

Before there was Keto, there was Atkins. It’s been around since the early 1970s, and is still with us even though Dr. Atkins isn’t (he passed away some 20 years ago). The basic guidelines are the same as the Ketogenic Diet, but you’re allowed to eat more protein and can gradually increase carbohydrate intake over time.

In short, Atkins is designed in four phases; at first your body is put into ketosis, leading to weight loss. But as you add carbs back into your diet over time, Atkins becomes largely a maintenance program since the body slips out of ketosis. It’s easier to follow Atkins than Keto guidelines, but Keto’s more likely to keep weight off.

South Beach Diet

This one was created by a doctor who liked much of what the Atkins diet did, but felt that it wasn’t heart-healthy. His South Beach Diet, which was a huge fad during the early 2000s, limits the saturated fat that’s a major part of the Atkins diet, while permitting foods like whole grains and fruit which contain “good carbs.”

The four-stage eating plan emphasizes lean proteins, non-starchy fruits and vegetables while eliminating “bad carbs” as measured by their glycemic index (GI). Foods with a high GI boost blood sugar faster, higher and longer than more-desirable low-GI foods, possibly leading to increased appetite, weight gain, diabetes and heart disease. The South Beach Diet isn’t as popular as it once was, but it still works for many people who want to lose weight and then maintain.

Mediterranean Diet

Not all nutritionally-sound diets are based on scientific theory; the Mediterranean Diet is based on experience. It centers on the foods eaten by people in nations like Greece and Italy during most of the 20th century, because those folks had virtually none of the weight or lifestyle disease issues which have become so prevalent in America.

The Mediterranean Diet is heavy on fish and seafood, vegetables and some fruits, nuts and seeds, whole grains and lots of olive oil. It eliminates sugar and foods sweetened with it, processed meats and oils, carbs made from processed grains, and (of course) processed and junk foods. Meat and poultry can be eaten only occasionally; beverages should be water, unsweetened tea and coffee, or red wine. This is a very healthy diet which leads to gradual weight loss and overall wellness.

Blood Type Diet

There’s no medical evidence proving the validity of the Blood Type Diet, but it’s been popular since the 1990s. In a nutshell, your blood type supposedly represents genetic traits passed down from your ancestors. Type A’s are “cultivators” and should eat a plant-based diet with no red meat, and type B’s are “nomads” who can eat almost everything but chicken, pork, wheat and tomatoes. Type AB’s are “enigmas” who should skip beef, chicken, kidney beans and corn, but can eat seafood, tofu, grains and dairy, and type O’s are “hunters” who should eat a high-protein diet limited in grains and dairy.

Does this diet make sense? Not in terms of blood types, but most of the actual “fine print” for each blood type spells out a different but healthy diet – so it probably won’t do any harm.

Diets Based on “Common Sense” Nutritional Approaches

DASH Diet

U.S. News puts out an annual ranking of the “best diets,” and the DASH Diet often ties with the Mediterranean Diet at the top of their list (4). This is a diet designed to fight high blood pressure (DASH stands for Dietary Approaches to Stop Hypertension), and it’s based on what mom always told you: eat lean meats and proteins with lots of fruits, veggies and whole grains, and skip the fatty stuff like soda and desserts.

There’s science behind the advice. The “good for you foods” are high in protein, fiber, calcium and potassium, all of which work to keep blood pressure down. One more problematic ingredient, salt, is also limited on the DASH Diet which is designed for long-term health first and weight loss second, and is promoted by the National Heart, Lung and Blood Institute. This is an excellent prediabetic diet choice.

MIND Diet

Here’s a diet that’s not aimed at fast weight loss; it’s been designed to lower the risk of mental decline and possibly lower the risk of developing Alzheimer’s Disease. A blend of the Mediterranean and DASH Diets, this one goes heavy on healthy foods that benefit the brain.

There are recommended amounts of each food or ingredient: leafy green vegetables and other veggies, berries, fish, poultry, whole grains, nuts, olive oil, beans – and a glass of wine each day. You can have other foods as well on the MIND diet, but the more of those ten top foods, the better.

American Heart Association Diet

This organization doesn’t offer an actual diet, but suggests a set of common-sense dietary recommendations to follow. It emphasizes a mix of nutritious foods from all food groups, combined with healthy lifestyle changes (primarily exercise) as the best way to control weight, blood pressure and cholesterol, and maintain heart health.

The AHA recommendations focus on good amounts of fruits and vegetables, whole grains, low-fat dairy, poultry and fish (without skin), legumes, nuts and “non-tropical” vegetable oils. Trans and saturated fats, red meat, sugar, salt, sweets and sweetened beverages, on the other hand, are strictly limited. Some programs we’ve mentioned, including the DASH Diet, fit these general guidelines.

Mayo Clinic Diet

Unlike the Heart Association, the Mayo Clinic has put together a specific diet to follow. In fact, it’s based on a diet the world-famous clinic published 70 years ago, and quite similar to the AHA’s recommendations. It preaches limited portion sizes, sets up a food pyramid (the biggest block is veggies and fruit and the smallest one is sweets), and lists 15 eating habits to develop (eat a healthy breakfast and use healthy fats like olive oil) or eliminate (don’t eat unhealthy snacks and don’t eat too much meat).

There are two phases in the Mayo Clinic Diet, two strict weeks in which you’re supposed to lose 6-10 pounds and then maintenance for “life.” Eating plans are designed to fit calorie restrictions based on sex and body weight; you have to get the details in a book, but it’s available pretty cheaply on eBay or similar sites. An online support system that costs $5/week is also available.

Jenny Craig Diet

Jenny Craig is just one of many weight-loss diets which are happy to take the guesswork and planning out of your diet – for a fee. Actually, there are several fees. One is to join and maintain a monthly membership, which also gives you weekly access to a “consultant” to help you with the diet and an exercise program. The other fee is for prepared meals (available for pickup or delivery) which are designed to provide dietitian-designed, low-calorie, low-fat, small-portion meals that only need to be reheated.

The meals are somewhat expensive but not bad, although you have to add your own fresh veggies and fruit and they only fill half your weekly food needs, at most. The real goal is to “teach” you what you should be eating, so you can eventually stop paying for the Jenny Craig food and prepare your own to create a healthy eating plan for life.

Diets Based on Calorie Counting and Similar Approaches

Weight Watchers Diet

Another fee-based diet program, Weight Watchers has been around forever even though they’ve rebranded to the catchier “myWW.” You don’t count calories per se on the WW diet; you count “points” that are assigned to different types of food, and you’re assigned a daily maximum point total. Healthier foods (lower calories, less saturated fat, less sugar and high-protein) are given lower point values, so you can eat more of them. You can eat other (tastier?) foods as well, but they have a higher point value so they use up your point allowance quickly.

It’s expensive and it’s not designed for fast weight loss, but people have used and loved Weight Watchers for years.

1200 Calories a Day Diet (or similar)

There are too many variations on this approach to detail here but they all involve counting calories, and 1200 is one of the most common limits that’s used. The theory is easy to understand: eat fewer calories than your body requires, and it will be forced to burn stored fat. 1200 calories is considered a good target for women in good shape, but most men will require a higher limit.

If the number is chosen correctly and you stick to the diet religiously, it’s one of the most reliable ways to lose weight. Unfortunately, strict adherence will also almost definitely leave you hungry and possibly weak, so most people find it exceptionally difficult to stick to a diet like this for anything other than short-term weight loss.

Diets Based on Philosophical Approaches

Vegan Diet

You probably know that vegans avoid the use of all animal products, although they do it because of different motivations. Some do it for philosophical reasons, some do it for environmental reasons, and some do it for the perceived health benefits. In brief, a vegan diet means no meat (including poultry and fish), no eggs and no dairy products.

There are many variations of this diet, but most do help with weight loss, lower blood glucose levels, lower blood pressure and prevent heart disease. Unfortunately, vegan diets are often lacking in important vitamins and minerals, so supplements are usually required. A radical version is the Raw Food Diet, in which the food can be dehydrated, juiced, blended – but not cooked.

Vegetarian Diet

Vegetarianism is different from veganism, although many don’t realize it. In general, vegetarians avoid eating any type of meat, but will eat either eggs, dairy products, or both. Reasons for adopting a vegetarian diet are similar to those just mentioned for vegans. Some of the variations on this diet include the pescatarian diet, which allows fish, and the flexitarian diet, which lets you eat meat occasionally.

The health pros and cons are similar to those of a vegan diet, and if supplemental nutrients aren’t included in some way, side effects can include fatigue, thyroid problems and anemia.

Paleo Diet

The rationales for a Paleolithic Diet (also sometimes called the Caveman Diet) can be philosophical, but are result-driven for most people. It’s based on the concept that we should return to the natural diet that our hunter-gatherer ancestors ate, millennia ago. Proponents believe humans develop many diseases and illnesses today because our bodies were never meant to eat the processed foods now so common.

The Paleo diet is loaded with raw vegetables, fruits and nuts along with some lean meats and fish (preferably grass-fed meat and wild game); no grains, legumes, dairy or sugar are allowed. It’s shown good results when used for weight loss, but can lead to calcium and protein deficiencies so many doctors advise against it.

Diets Based on Medical Necessity

Gluten-Free Diet

While eliminating gluten (found primarily in bread and other wheat products like pasta and pizza) is a virtual necessity for those with celiac disease and gluten intolerance, the gluten-free diet has helped many others lose weight as well – eliminating most carbs from a diet will do that. This diet’s popularity has led to a huge surge in the availability of gluten-free products in supermarkets.

GERD Diet

About one-fifth of Americans have some degree of gastrointestinal reflux, which causes heartburn and chest pain. Triggers vary between sufferers, but generally speaking, a GERD diet limits or eliminates fatty meats, most oils, salt, and dairy products rich in calcium. This isn’t an unhealthy diet for non-sufferers, but there are better options for weight loss.

Gallbladder Diet

The gallbladder is one of those organs you forget (or don’t realize) is there, unless you develop incredibly painful gallstones. In severe or recurrent cases, the organ is removed, but a special diet can help those with occasional issues. Foods that are low in fat and cholesterol help the most, while whole-milk and cheese, fatty meats, fried and processed foods are avoided. A gallbladder diet is better for your health than the average American’s diet, too.

Crohn’s Disease Diet

There are two elements of a diet that’s suitable for those with the severe intestinal pain of Crohn’s Disease. One is to avoid specific food triggers, which differ from patient to patient but usually include alcohol, caffeine, fruits and vegetables, and fatty foods. The other is to overcome the nutrient deficiency that’s common due to a loss of appetite, normally with a high-calorie, high-protein diet that includes regular meals and snacks.

SIBO Diet

Many undiagnosed stomach problems are due to an overgrowth of bacteria in the small intestine, and the SIBO diet (Small Intestine Bacterial Overgrowth) is aimed at reducing both the bacteria and the inflammation they cause. The key (along with antibiotics) is a diet that’s low in hard-to-digest carbs known as FODMAPS, like grains, artificially-sweetened products, smoked or dried foods and many vegetables and fruits. This isn’t an overly healthy diet for most people, but it’s important for those who need it.

Hashimoto Diet

The thyroid autoimmune disease known as Hashimoto Disease often causes hypothyroidism, which greatly affects the body’s metabolism – and is one possible hidden cause of weight gain. Doctors often recommend diets which provide anti-inflammatory effects for their Hashimoto patients; gluten-free, Paleo and vegetarian/vegan diets are common options.

Liquid Diet

A liquid diet is a vital first nutritional step when you’re recovering from many surgeries. Some people, though, see it as a quick path to weight loss. It can be – but most liquid diets don’t include enough key nutrients to sustain the body’s metabolism. A liquid diet is almost always a bad idea unless it’s done under medical supervision (perhaps to treat gross or morbid obesity), and in consultation with a nutritionist.

Fad Diets

Most fad diets come and go so quickly that it’s hard to maintain a current list. Here are a few which have been around for at least a few years.

• Cabbage Soup Diet: Nothing but the soup for a week; simply temporary weight loss and the danger of being grossed out for a week.
• Apple Cider Vinegar Diet: A spoonful with every meal; may help body alkalinity, may hurt tooth enamel, and no proof it helps you shed pounds.
• Intermittent Fasting: Many varieties; difficult for people to stick with and doesn’t lead to major weight loss.
• Tom Brady Diet (TB12): Now more popular in Tampa than Boston; mostly organic and plant-based foods, healthy but expensive and doesn’t supply some needed nutrients.
• Honey Diet: Replace sugar with honey and you can lose pounds every week? Well, the rules also say you basically have to follow the other rules of a high-carb diet, too.