The Most Effective Diets According to Experts

Mediterranean Diet

The Mediterranean diet ranked at the very top yet again in 2022—the fifth year in a row, in fact. The eating pattern has long been considered the gold standard for nutrition, disease prevention, wellness, and longevity.

There really isn't one single Mediterranean diet. For example, people in Greece eat differently from those in Italy and Spain. While the traditional diets in this region share many of the same principles, the Mediterranean diet is an eating style and way of life, not a rules-oriented diet. That said, you may lose weight simply by shifting your intake away from processed foods and toward more fiber- and nutrient-rich produce and whole foods.

Features of the Mediterranean Diet

The diet is rich in vegetables, fruits, whole grains, nuts, pulses (i.e., beans, lentils, peas, chickpeas), and olive oil.
It calls for fish at least a few times per week and allows for poultry, eggs, and dairy in moderation.
It severely limits processed foods, added sugar, and red meat.
The diet encourages at least two and a half hours per week of moderate-intensity activity, along with a few days of muscle-strengthening exercises, and these can include recreational activities like walking and gardening.

This diet naturally provides a wide range of anti-inflammatory antioxidants, including those from moderate amounts of red wine. Note that wine is not a requirement of the diet, but one 5-ounce glass per day for females and two for males is typical for those who follow the diet.

Benefits

The Mediterranean diet is nutritionally sound and balanced and provides a diverse array of filling, satiating foods, and flavors.

A 2020 review published in the British Journal of Pharmacology said that numerous studies support the diet's ability to improve outcomes for metabolic syndrome, type 2 diabetes, heart disease, obesity, and cancer. According to the Centers for Disease Control and Prevention (CDC), heart disease remains the top killer of US adults.

A 2018 Italian study in the journal Nutrition & Diabetes found that following a Mediterranean diet was associated with lower levels of weight gain and less of an increase in waist circumference over a 12-year period.

Disadvantages

There are no guidelines for specific portions, calorie targets, or meal configurations, which can be frustrating for some.

And the Mediterranean diet can potentially be costly, although, you can reduce your grocery bill by buying certain foods like in-season produce, bulk grains, and canned beans.

The diet also generally requires cooking. If you'd like to follow the plan with a bit more structure, consider consulting with a registered dietitian who can help you determine how to plan Mediterranean meals tailored to your personal needs and goals. You can also look for meal delivery services, cookbooks, and other online resources that support the plan, of which there are plenty of options.

DASH Diet

Slotting in at number two once again on the 2022 list was the Dietary Approaches to Stop Hypertension Diet, which is more commonly known as the DASH diet. This diet is not just for people with high blood pressure. DASH is promoted by the National Heart, Lung, and Blood Institute, which is part of the National Institutes of Health (NIH).

Features of the DASH Diet

This plan borrows elements of the Mediterranean diet, but it is a very specific eating pattern.

According to the NIH, the DASH eating plan recommends specific portions from various food groups, depending on a person's daily calorie needs. For example, a 1600-calorie DASH diet (a typical calorie level for females over 40) includes the following:

6 servings of grains daily, with an emphasis on whole grains
3 to 4 servings of vegetables daily
4 servings of fruit daily
2 to 3 servings of low-fat dairy daily
3 to 4 ounces or less of lean meat, poultry, or fish daily
3 to 4 servings of nuts, seeds, and legumes per week
2 servings of fats and oils daily
3 or fewer servings per week of sweets
A maximum of 2,300 milligrams per day of sodium

The word "diet" may suggest a temporary or quick-fix approach, but DASH is meant to be followed for the long haul. The plan is recommended as part of a lifestyle that also includes limiting alcohol, coping with stress, being physically active, not smoking, and getting plenty of sleep.

Benefits

In addition to being effective for reducing blood pressure, the highly researched DASH diet has been shown—according to a 2022 review published in StatPearls—to promote weight loss, protect heart health, and lower the risk of type 2 diabetes and stroke.

DASH has actually been in existence for over two decades. It's fairly straightforward, and while the rate of weight loss with DASH can be slow, it's sustainable long term.

Disadvantages

One drawback is the lack of obvious alternatives to animal protein for those who are looking for a plant-based plan. It's also a bit low in healthy fats. Since the diet is very specific, if you're looking to tailor the plan to your preferences, consult with a dietitian for a customized DASH plan.

Flexitarian Diet

"Food blogs were aflutter this year over 'flexitarian,' the latest word in gastronomic circles," the New York Times reported back in 2004. Nearly two decades later, the diet is still going strong, tying at second for another year.

Features of the Flexitarian Diet

In a nutshell, a flexitarian diet is primarily a vegetarian diet, with the occasional inclusion of animal protein.

However, there is no one way to follow a flexitarian diet—there is no one universal guideline on the number of times per week animal products are consumed or on what the overall makeup of a day's worth of meals should be in regards to servings of produce, whole grains, etc.

The best way to follow the overarching flexitarian plan for weight management and overall health is to maximize your intake of whole, plant foods and minimize highly processed foods, even if they are fully plant-based. In other words, opt for dishes like a grain bowl made with leafy greens, veggies, quinoa, lentils, and tahini over a vegan cheeseburger with fries.

If the bulk of your meals is comprised of a variety of whole, plant-based foods, and plant proteins, you can enjoy occasional servings of animal foods while reaping a number of nutrients and health benefits.

Benefits

Since the term began buzzing, numerous studies, including a 2016 research review in the journal Frontiers of Nutrition, have shown that the shift toward a mostly plant-based diet is tied to lower body weight and a reduced incidence of chronic diseases, including improved markers of metabolic health, blood pressure, and reduced risk of type 2 diabetes.

A study from 2020 in the journal Appetite found that young adults don't view flexitarianism as an all-or-nothing approach—"one does not have to be a full vegetarian or a meat eater, but can instead be something in between," the researchers wrote about the participant's outlook on the diet.

Disadvantages

While the diet's flexibility can be viewed as an advantage, there has been a movement to better define and categorize different approaches for those who want a more concrete label. A 2021 study in the journal Appetite segmented flexitarian diets into three types:

Climatarian (limit beef and lamb consumption)
One step for animals (eliminate chicken consumption)
Reducetarian (reduce all meat consumption)

Considering which of these you want to follow could help you if you are looking for a more clearly defined diet.

The MIND Diet

Moving up from the fifth spot on the 2021 list, MIND combines aspects of the Mediterranean and DASH diets to create an eating pattern designed to focus on brain health. Even though its main targets include preventing dementia and age-related cognitive decline, the MIND diet can be followed by anyone for weight loss and overall wellness.

MIND stands for the Mediterranean-DASH Intervention for Neurodegenerative Delay. Because both the Mediterranean and DASH diets have such strong research to support their healthfulness, MIND highlights aspects of the two that are particularly protective of the brain.

Features of the MIND Diet

Rather than a set meal plan, MIND's primary directive is to eat more of the 10 brain-defending foods, which are:

Green, leafy vegetables—Aim for six or more servings per week.
All other vegetables—Get in at least one serving a day in addition to your leafy greens, particularly non-starchy veggies.
Nuts—Have five or more servings weekly.
Berries—Eat them at least twice a week.
Beans—Take them in at least four times per week.
Olive oil—Use it as the main prep and cooking oil.
Whole grains—Include at least three servings per day.
Fish—Eat it at least once a week, particularly fatty fish high in omega-3s, like salmon, sardines, mackerel, trout, and tuna.
Poultry—Aim for un-fried chicken or turkey twice a week or more.
Wine—Drink no more than one glass daily, and make that glass of red wine.

The plan also lays out five foods to avoid, as they have been shown to hinder brain health:

Butter and margarine—Limit to less than 1 tablespoon per day.
Cheese—Stick to once per week or less.
Red meat—Have no more than three weekly servings.
Fried food—Limit to less than once per week.
Pastries and sweets—Consume no more than four times per week.

Benefits

Since MIND is newer than both the Mediterranean and DASH diets, there are fewer studies on its outcomes. However, the research on its health benefits that have been published is impressive. In one 2015 study in the Alzheimer's & Dementia journal of nearly 1,000 older adults, those who followed the MIND diet most closely had a 53% lower risk of developing Alzheimer's disease compared to those who deviated from it most.

U.S. News & World Report cites a 2021 study, which found that the MIND diet may have protective effects against Parkinson's disease. Starting MIND at about age 65 was associated with delaying Parkinson's onset—up to about 17 years later for women and eight years for men, according to the study.

Disadvantages

As for weight loss, 2020 research in the Nutrition Journal of more than 6,500 participants with obesity found that the following MIND had no impact on body weight or waistline size.

One possible reason for the lack of weight loss—and another downside of the MIND diet—is a lack of information about how to transform its guidelines into concrete meal plans and recipes. There are books and online resources to help, but customizing the plan to your eating preferences and weight loss goals may require some expert guidance.

Mayo Clinic Diet

Staying tied in the fifth position is the Mayo Clinic diet.

Features of the Mayo Clinic Diet

This diet follows a 12-week program that involves eating unlimited veggies and fruit, consuming whole grains and healthy fats, and limiting sugar to what's naturally found in fruit.

The plan includes two phases:

The first, called "Lose it!" touts weight loss of six to 10 pounds in two weeks by focusing on lifestyle habits that are associated with weight.
After two weeks, the next phase, "Live it!" focuses on how to consume your calories—though that's not something you have to count—in a healthful, balanced way.

The diet stresses a long-term, maintainable lifestyle approach.

Benefits

This diet is from the highly esteemed US academic medical center that focuses on integrated health care, education, and research. The eating plan is based on research-backed, tried, and true healthy habits.

Sample meals, based on various eating styles, such as vegetarian, healthy keto, and Mediterranean diets can be viewed on the Mayo Clinic's website.

Disadvantages

Some people might not like the fact that this diet may involve a subscription program. An all-new digital version of the program is offered for $49.99 per month, or as low as $19.99 per month if you sign up for a year. It includes meal plans, recipes, a food tracker, virtual group video sessions, access to a private Facebook group, at-home workouts, a psychological quiz to assess diet mindset, and guidance on behavior change, nutrition, sleep, stress management, and goal setting.

TLC Diet

TLC stands for therapeutic lifestyle changes, and it broke its way into the top five in 2022. The plan was originally created in 2002.

Features of the TLC Diet

The dietary component calls for:

25–35% of daily calories from total fat, with:
Less than 7% of daily calories are from saturated fat
Up to 10% of total calories are from polyunsaturated fat
Up to 20% of total calories are from monounsaturated fat
50–60% of total calories from carbohydrates with:
20 to 30 grams per day of dietary fiber
Approximately 15% of total calories are from protein
Less than 200 milligrams a day of cholesterol
Additional options for reducing LDL cholesterol, include consuming two grams of plant stanols or sterols per day or 10 to 25 grams of soluble fiber per day
Only enough calories to reach or maintain a healthy weight

TLC also advises at least 30 minutes of moderate-intensity physical activity, such as brisk walking on most, and preferably all, days of the week.

Because TLC recommends 20 to 30 grams of fiber daily, whole foods like vegetables, fruit, pulses, nuts, and whole grains are encouraged. This also fits with the 200 milligrams per day limit on cholesterol, as dietary cholesterol is not found in plant-based foods. And the allowance of up to 20% of calories from monounsaturated fat makes TLC avocado- and extra virgin olive oil-friendly, giving it some alignment with the top-ranked Mediterranean diet.

Benefits

Published by the National Institutes of Health, TLC advocates for taking control of your heart disease risk by adopting a heart-protective lifestyle. Designed as a way to manage cholesterol, the TLC guidelines may also help you lose weight and lower your risk of other chronic illnesses.

Disadvantages

There are also a handful of cons. The high percentage of calories from carbs and modest allotment of protein may be slightly off base for some. Carbs are often recommended to cap at 40% of calories for less active people or those with lower energy needs, including older adults. And active people often require a higher protein intake, depending on their exercise regime and goals.

The other challenging aspect of TLC is translating the numbers into practical meals. Plus, many of the diet's suggestions are also outdated. For example, one suggestion is to opt for Jell-O as dessert, but that's high in sugar and low in overall nutrients. With the current emphasis on whole foods and a reduction in added sugar and highly processed foods, TLC could use an update.

If you decide to give it a try, consider modernizing the plan with a focus on whole foods. And if you need help personalizing the plan based on things like food allergies or intolerances, or how to adapt it to a very active lifestyle, consider meeting with a registered dietitian nutritionist.

Volumetrics Diet

Many people believe that weight loss requires eating less. That's absolutely not the case, and the Volumetrics diets prove it. The plan, which was originally developed by Penn State nutritional sciences professor and researcher Barbara Rolls, PhD, more than 20 years ago, is all about filling up by eating a larger volume of food, while simultaneously slimming down.

Features of the Volumetrics Diet

While no foods are off limits, the idea is to focus on energy density, aka the number of calories in a given portion of food. Foods with high-energy density pack more calories for a relatively small portion, whereas low-energy-density foods are low in calories for a larger volume.

Low-energy-density foods are encouraged. These include water-rich, non-starchy veggies and fruits as well as broth-based soups.
Whole grains, lean proteins, beans and lentils, and low-fat dairy products are allowed in moderate portions.
Bread, cheeses, and higher-fat meats are limited to small portions.
And fried foods, sweet treats, and candy are allowed sparingly.

Rather than laying out exactly what to eat, you are able to choose. But when you select high-energy-density foods, your portions must shrink. The idea is to fill up on low-energy-density foods, which are generally healthier and more nutrient-rich, like salads, broccoli, and fresh fruit. For example, you can eat a cup of seedless grapes, about the size of a tennis ball, for the same number of calories as two small cookies. Keeping a food diary is encouraged.

Physical activity is also encouraged, starting with an additional 150 steps per day, with a goal of eventually hitting 10,000 steps daily.

If you try Volumetrics, focus on upping your portions of low-calorie whole foods first, balance with moderate to smaller portions of higher-calorie whole foods, and can't live without treats in moderation.

Benefits

The plan estimates a weight loss of one to two pounds per week, but while the plan is research-backed, the research is a bit dated. However, several studies, including some conducted by Rolls herself, support the overall approach in terms of weight loss outcomes. A research study coauthored by Rolls and published in 2007 in the American Journal of Clinical Nutrition stated that the diet "is an effective strategy for managing body weight while controlling hunger".

One key pro to the Volumetrics diet is that no food is completely off-limits. Plus, the diet emphasizes how to build in can't-live-without splurges in a balanced way, which better supports long-term sustainability.

Disadvantages

As far as cons, the diet does require a good understanding of Volumetrics, which involves learning about the various calorie levels of foods in relation to both portion sizes and nutrient levels, which may be cumbersome for some.

And the central premise of the diet may not always hold true. For example, you might feel far more satisfied with a mere quarter cup of nuts, a few tablespoons of nut butter, half of an avocado, or a few squares of dark chocolate compared to a much larger volume of popcorn, raw veggies, or fruit. In other words, volume alone doesn't always correlate with satisfaction.

Also, the approach could encourage filling up on low-calorie, highly processed "diet" foods, including those made with faux sugars. Not only are these products devoid of nutrients, but they contain artificial sweeteners. These sweeteners may affect appetite regulation, according to research published in 2021 in JAMA.

WW (formerly Weight Watchers) Diet

WW ranks highly because it is well-researched, long-standing, and not extreme in its approach. The newest version, called the PersonalPoints Program, is customized based on each member's personal food and lifestyle preferences.

Features of the WW Diet

WW members have access to meal planners and more than 10,000 recipes; food, water, weight, and activity trackers; a restaurant database; on-demand workouts; 24/7 chats with a coach; weekly progress reports; and more.

Benefits

As for weight loss, U.S. News & World Report cites a 2017 study published in Lancet that looked at more than 1,200 patients who had overweight or obesity. Researchers found that assigning participants to a WW program for at least 12 weeks was more effective than providing brief advice and self-help materials for weight loss.

WW can work well for people who on thrive on being part of the community and using digital tools and who also prefer an eating plan that provides structure and accountability but that allows for flexible choices.

Disadvantages

Some may view the membership model as a drawback. The cost, which varies based on the chosen plan, can be as low as about $13 per month for a three-month membership.

The 3 Diets That Ranked Lowest

The diets that rated the lowest on the list were the GAPS diet, the Dukan diet, and a modified keto diet. While each of these three plans may result in initial weight loss, experts fear they may not allow for stick-with-it-ness, an important point to take into account if you're considering adopting any new diet.

GAPS Diet

GAPS stands for the gut and psychology syndrome diet. It's an elimination diet created by Natasha Campbell-McBride, MD, to treat gut and psychology syndrome, a term the author coined to describe the connection between the health of a person's digestive system, brain, and rest of their body.

The U.S. News & World Report panel ranks it low due to:

A lack of research supporting its claims
The level of difficulty to maintain the diet
The cost

The diet requires you to eliminate foods and then reintroduce them one at a time to find out which may be causing symptoms, such as digestive issues and poor brain function. The approach involves a six-phase strict detoxification process, followed by the full GAPS eating regimen, which incorporates fish and meats, animal fats, eggs, fermented foods, and vegetables. All foods should be organic and fresh, and there is a long list of GAPS-specific foods to avoid, including all processed foods.

Dukan Diet

The Dukan diet is a high-protein plan that claims to allow up to 10 pounds of weight loss within the first week, with a continued loss of two to four pounds per week until you've reached your weight loss goal.

It requires four phases and lays out a number of strict rules, including:

Consuming a daily portion of oat bran, with amounts that differ based on the phase of the diet
Limiting vegetables and fruits to only the short list of those allowed, which can only be consumed on certain days
Limiting starches, such as beans, rice, and potatoes, to just one or two servings per week during the third phase of the diet

It rates low by U.S. News & World Report based on its difficulty and potential nutrient shortfalls. As for weight loss and health outcomes, no clinical trials have been published to evaluate the Dukan diet.

Modified Keto

The modified keto diet is a low-carb, high-fat plan that calls for a bit less fat than a traditional keto diet—50% to 65% of total daily calories as fat compared to up to about 90% in a standard keto plan.

Even though the modified diet may be a bit easier to follow than the traditional keto diet, it ranks low by U.S. News & World Report based on its restrictiveness.

A Quick Review

There are a variety of effective and healthy diets, and there are probably a few that would work well for you. So pick the one that makes the most sense for you.

If a diet helps you lose weight but compromises your physical or emotional well-being or social life, it's not a healthy, sustainable option. If you can't realistically see yourself following a given diet six months or a year down the road, it's probably not the right approach for you and will likely result in health issues or regaining all—and then some—of the weight you lose.

Weight management and health aren't about being restrictive. Keeping weight off is about developing habits you can stick with long term. The ultimate formula is really about balance and quality of life.

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