The 12 Best Diets for Fast Weight Loss

Quick and dirty Does bikini season sneak up on you each summer? Is your soon-to-be worn wedding dress still just…

Quick and dirty

Does bikini season sneak up on you each summer? Is your soon-to-be worn wedding dress still just a touch too tight? Were your holiday outfits uncomfortably snug? Did a last-minute invite for a beach getaway come your way? You’re a lucky dog — and a panicked one too because you want to drop pounds, and fast.

These 12 diets are likely to help you lose significant weight within a year, according to a panel of experts who reviewed 40 plans for the U.S. News Best Diets rankings. Just remember: Short-term weight loss is markedly different from long-term weight loss, which is more important for your health.

No. 7 (tie) Jenny Craig Diet

Jenny Craig‘s prepackaged meals and recipes help participants lose weight — up to 2 pounds a week, it says — through restricting calories, fat and portions. One systematic review of more than 120 studies suggests it works: Jenny Craig was among the most effective in terms of six-month weight loss, reaching nearly 17 pounds. However, at one year, overall weight loss diminished for all diets in the study.

Experts deem Jenny Craig “very effective” for short-term weight loss, some praising its focus on teaching proper portion sizes and helping dieters learn to eat when they’re hungry, rather than when they’re bored or emotional.

No. 7 (tie) Nutrisystem Diet

Nutrisystem is safe and easier to follow than many other diets, according to experts. The pre-portioned, low-calorie meals may make Nutrisystem particularly helpful in early dieting. “Packaged foods can become boring after so many months, but at least it takes the decision out of ‘What do I eat today?’” an expert notes.

Another pro’s take: “I recommend it to those who are not fond of cooking. I wouldn’t recommend it to those who love to eat fresh foods.”

No. 7 (tie) Raw Food Diet

The raw food diet earns solid marks for weight loss, but it’s considered all but impossible to follow. In addition, its nutritional completeness and safety are questioned by experts who raise concerns about the potential for food poisoning from contaminated ingredients that are raw or undercooked.

“More research is needed on the raw foods approach,” one expert says. “I believe it may have tremendous health benefits and may help protect against heart disease, diabetes and related health problems. Unfortunately it is very hard to follow, and we don’t know enough about how to use the raw foods approach safely.” Another reviewer harrumphs: “Lots of unnecessary rules,” “based on false assumptions” and “I can’t imagine sticking to this long term, nor would I want anyone to.”

No. 7 (tie) SlimFast

SlimFast is designed to make cutting calories simple and fast weight loss likely, with products like shakes, smoothies and meal bars replacing two meals a day and snacks. “Meal replacements are supported in studies to help promote weight loss and weight maintenance,” one U.S. News expert says.

But as with most diets that do well in the fast weight-loss category, SlimFast lacked in other departments, like heart health and sustainability. If you’re aiming to lose more than 20 pounds (which should take about 10 weeks on this plan), SlimFast may not be your best bet.

No. 7 (tie) Vegan Diet

The value of a vegan diet is the focus on fruits, vegetables, legumes and whole grains, preferably using low-fat preparations, according to one expert. And scientific evidence is overwhelming that increasing these foods and decreasing animal foods is beneficial for weight, and prevention and management — and possible reversal — of many chronic diseases.

Following a vegan diet is a lot more involved than just taking out animal products, though. There are a lot of vegan “junk food” options out there, one expert says, so just because something is vegan doesn’t necessarily make it healthy.

No. 7 (tie) Volumetrics Diet

By filling up on bulky foods with few calories (think carrot sticks rather than cashews), as the volumetrics diet dictates, you’re likely to lose significant weight during the first year, U.S. News expert panelists say (1 to 2 pounds per week to be exact, according to the company).

The plan is praised for teaching dieters portion control and how to choose foods that are low in calories but keep you feeling fuller longer. It’s also a “different and effective approach that is uncomplicated and flexible — what most people need to stay with any eating plan,” one pro says.

No. 4 (tie) Biggest Loser Diet

If you ever saw the TV show, you get the idea: Six weeks of healthy food and regular exercise is celebrated as a great start to a weight-loss journey — as well as a way to prevent or reverse various diseases. Fair enough.

Experts determined that the Biggest Loser diet is very likely to help you shed pounds, thanks to calorie restriction and exercise. But a 2016 study suggests the diet can lead to a permanent dip in metabolism, and experts also worry that the exercise guidance — as much as three hours a day — is excessive and a lot harder for regular folks than TV stars-in-the-making.

No. 4 (tie) Keto Diet

Butter, bacon, burgers, oh my! Meals consisting of high-fat foods like these are hallmarks of the keto diet, an extremely low-carb, high-fat plan that aims to send you into ketosis, a state in which your body is forced to burn fat, not sugar, for energy.

Though quick weight loss is indeed likely on the keto diet, experts don’t recommend it for most people since it lacks nutritional variety and is unsustainable long term. As one expert puts it: “It is a rigid diet, it is not environmentally friendly and we don’t have epidemiological evidence of populations eating this way.” In other words: Follow at your own risk.

No. 4 (tie) WW (formerly Weight Watchers) Diet

WW — a plan that uses a point system to encourage followers to choose healthy, filling foods — claims you can shed up to 2 pounds a week. Our experts back its ability to deliver quick results. Better yet? Those results are likely to last, thanks to the program’s emphasis on a balanced diet with no restrictions, as well as its built-in support system.

“This is a tried-and-true plan with a proven track record, plus tools and support to help people succeed,” one expert concludes.

No. 2 (tie) OPTAVIA Diet

OPTAVIA, a brand from the team behind Medifast, is bound to lead to weight loss in most adults. After all, you’ll likely be limited to 1,000 calories a day coming from one daily meal and five 100-calorie “fuelings,” whether shakes, bars, eggs, oatmeal, pancakes, pudding, soup, brownies or even cheese puffs.

But don’t expect to stay on this plan longer-term: One U.S. News expert calls the products “unpalatable” and, on the whole, OPTAVIA ranks less-than-optimally on metrics like safety and nutrition.

No. 2 (tie) HMR Program

The HMR Program (Health Management Resources Program) uses meal replacements — think low-calorie shakes, meals, nutrition bars and hot cereal — in phases, coaching from experts, physical activity and an emphasis on fruits and vegetables to help dieters shed pounds fast.

“This diet makes it easy to lose weight fast and would likely be effective for someone who wants to lose weight for a specific event,” one U.S. News expert says. “However, as far as long-term healthy-habit-forming, this diet falls short,” in part because dieters don’t learn to make their own healthy food choices.

No. 1 Atkins Diet

A large part of the appeal of the Atkins diet, which aims to burn fat by limiting carbs and packing in fat and protein, is its claim of quick weight loss — as much as 15 pounds in two weeks, according to the company.

Our experts agree that’s a legitimate pitch, but note that much of the initial weight loss is water, due to the diet’s diuretic effect. “That means that the short-term weight loss looks much better than it really is, and when you stop the program, all the water comes back on,” one expert points out.

Best Fast Weight-Loss Diets

— No. 1 Atkins Diet.

— No. 2 (tie) HMR Program.

— No. 2 (tie) OPTAVIA Diet.

— No. 4 (tie) Biggest Loser Diet

— No. 4 (tie) Keto Diet.

— No. 4 (tie) WW (formerly Weight Watchers) Diet.

— No. 7 (tie) Jenny Craig Diet.

— No. 7 (tie) Nutrisystem Diet.

— No. 7 (tie) Raw Food Diet.

— No. 7 (tie) SlimFast.

— No. 7 (tie) Vegan Diet.

— No. 7 (tie) Volumetrics Diet.

More from U.S. News

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11 Tips for Quicker Weight Loss

Ways to Shift Your Mindset for Better Weight Loss

The 12 Best Diets for Fast Weight Loss originally appeared on

Update 01/04/22: This story was previously published at an earlier date and has been updated with new ranking results.