Should you try keto, flexible or full-on vegetarian, or some other plan? Dieting is tough, but the likelihood of your success may depend on which one you choose.
We chatted with a few registered dietitians to learn more about the diets they want to see stay — and those they’d be happy to see go.
The 4 Best Fad Weight Loss Diets in 2019
1. Mediterranean Diet
U.S. News & World Report ranked this mostly plant-based eating approach its No. 1 overall diet in 2019, and registered dietitians such as Amy Gorin, RDN, owner of Amy Gorin Nutrition in New York City, stand by that choice. Gorin applauds the Mediterranean diet — which is rich in whole vegetables, fresh fruits, whole grains, fatty fish, olive oil, nuts, legumes, and some red wine and dairy — because it’s a balanced way of eating. The Mediterranean diet’s focus on choosing whole, plant-based foods over those you might find in a vending machine may make you more likely to stick with it.
Beyond weight loss, there are the health benefits associated with eating like Italians, Greeks, and other people who live on the Mediterranean Sea (the diet’s namesake). This approach, Gorin says, alsosupports heart and brain health. For example, a review published in the journal Metabolic Syndrome and Related Disorders suggested that a Mediterranean diet, especially when combined with exercise and followed for longer than six months, was associated with reduced weight gain. The review involved 16 randomized controlled trials, which represented 1,848 people following a Mediterranean diet and 1,588 people who acted as the controls.
Weight loss and a healthier body? Win-win!
2. WW (Formerly Weight Watchers)
You know this popular weight loss plan by its previous name: Weight Watchers. But in 2018, the company rebranded to make the program more about wellness than just losing weight, per an explainer on the WW website. “This program is one of the most effective weight loss programs out there, promoting long-lasting, sustainable changes with many studies to back this up,” says Gorin, who writes a nutrition blog, called The Eat List, for WW. The newest version of WW, Gorin says, offers tangible rewards, like fitness class passes and travel shoe bags, when members reach their goals, delivering more incentive to lose. Also, “This year U.S. News ranked WW as the best diet for weight loss,” she says.
3. Vegetarian Diet
It’s difficult to call a vegetarian diet — one where you don’t eat meat — a “fad,” as there are so many reasons for going vegetarian, including environmental and ethical considerations.
Weight loss, though, is a potential benefit of opting to eat plants instead of meat, according to a review of 12 randomized, controlled trials representing about 1,150 people, published in January 2016 in the Journal of General Internal Medicine. Indeed, the Mayo Clinic notes that when you pay attention to portion size, a vegetarian diet can help with weight loss because the foods you’ll eat (including fruits, veggies, whole grains, and plant-based protein) contain fewer calories and fat but are more filling than foods found in a standard American diet.
Boosting your health may be another reason to adopt a vegetarian diet, and there’s science behind this choice. When carefully planned, “a vegetarian diet is a wonderful diet,” as it is rich in plant foods and low in saturated fat, says Jeanne Tiberio, RD, a tutor with Varsity Tutors based in Salem, Massachusetts. In a meta-analysis published in November 2017 in the journal Critical Reviews in Food Science and Nutrition, a vegetarian diet was associated with a 25 percent lower risk of heart disease and 8 percent reduced odds of cancer.
A word of caution: If you have a personal history of eating disorders, you may want to sidestep this approach. An study published in August 2012 in the Journal of the Academy of Nutrition and Dietetics noted that some people use a vegetarian diet to legitimize food restriction to aid with weight loss. There can be many perks to going veg — but play it safe and ask yourself where your motivations lie before making this choice.
4. Flexitarian or Semi-Vegetarian Diet
Whereas vegetarian eschews meat, a flexitarian diet allows you to add small amounts of animal products, like meat, poultry, or fish, for additional protein and satisfaction. If you’re a meat lover looking to burn calories in a balanced way, this flexible approach may be a good match for you. “Diets don’t have to be all-or-nothing,” says Tiberio.
Reducing, but not necessarily eliminating, how much meat you eat is generally a positive. For instance, one review of 25 studies published in December 2016 in the journal Frontiers in Nutrition found that semi-vegetarian diets were associated not only with weight loss, but also with health benefits such as lower blood pressure and a reduced risk of type 2 diabetes. The authors concluded that although it’s a popular eating approach with women, men, too, may benefit — especially because guys generally consume more meat.
1 Diet That Lands in the Middle: Intermittent Fasting, or IF
Intermittent fasting (IF) has become an increasingly popular way to lose weight fast. The approach involves extended periods of not eating, and there are several ways to tackle it.
For instance, some people fast for two days out of the week (called 5:2, which involves eating very little on fast days), while others set a specific eating window (like 16 hours fasting, 8 hours feeding).
While this is a growing approach and there is some evidence that it can help people lose weight at least in the short term, per the Harvard T.H. Chan School of Public Health, it’s not right for everyone, and that’s why it lands somewhere in the middle.
You really have to understand your needs and your schedule to know if it will work for you. “The eating style has a very restrictive nature and could lead to overeating or binge eating, so it’s not a good fit for a person with a history of disordered eating,” says Gorin. Also, if you have type 2 diabetes or are pregnant or lactating, IF is also not safe, she says.
The 5 Worst Diets for Weight Loss in 2019
1. Carnivore Diet
The increasingly popular carnivore diet requires eating mostly meat (along with some eggs and fat, like cheese). There’s also a popular version that involves eating only beef. Although you can find carnivore dieters’ success stories online, don’t even think about it, says Gorin: “This is not a healthy or sustainable diet, and there are healthier ways to lose weight.”
“Not only is the carnivore diet extremely high in saturated fat, which can put you at risk for increased cholesterol levels, it also leaves out a lot of foods that are really good for you,” Gorin says. That includes fruits and veggies, which are known to promote weight loss and help fight disease.
Bottom line: Avoid this diet — or if you’re determined to try it, be sure to run the idea by your healthcare team and get their take first.
There’s nothing wrong with the foods that Whole30 asks you to eat, like fresh fruit and veggies. In fact, proponents of the plan say that focusing on whole foods instead of packaged, processed ones may result in weight loss and other health perks, too, like higher energy and improved sleep.
But the Whole30 plan prohibits eating many dietary staples — not just unhealthy foods like added sugar and alcohol, but also legumes, dairy, and grains. And while your body doesn’t need those healthy foods to function, Whole30’s restrictions can make the program difficult to stick with.
Furthermore, those rules can create a cycle of guilt around food, says Anne Mauney, a registered dietitian in Washington, DC. Even if you follow through on the entire 30-day program, at the end you’re likely still going to feel down on yourself for eating what was once deemed “bad.”
Plus, when you go back to eating these foods, “you may likely end up eating more of it than you need or want, because there’s that sort of ‘screw it’ mentality where you’ve already started eating something you ‘shouldn’t’ have, so you might as well keep going. This can often turn into a sort of ongoing restrict-binge cycle over time, where you limit certain foods and then end up overdoing it on those foods later, before going right back to restricting and trying to be ‘good,’” she says. That’s no way to live.
3. Keto Diet
If you want to lose weight quickly, this diet, which researchers designed to help control epilepsy in children, has become a popular way to do so.
But there’s a lack of definitive research proving that keto is safe and effective for the long haul. What we do know is this high-fat, moderate-protein, and very-low-carb diet has a reputation for being challenging, especially if you’re doing it without medical supervision. When you go off the plan, you might gain back all the weight you lost.
What’s more, for all the buzz about the health benefits of keto (for type 2 diabetes, certain types of cancer, Alzheimer’s disease, and more), long-term randomized, controlled trials in humans are lacking, Harvard notes. “Keto restricts foods that help fight cancer and heart disease, like whole grains and legumes,” says Tiberio.
What’s more, there are so many ways to approach keto, and not all of them are healthful. “Though you should be eating a lot of spinach and kale on keto, people generally eat bacon and eggs,” says Tiberio, which leaves out important disease-fighting nutrients, including fiber.
Of course, the Atkins diet was the original low-carb diet, made popular decades ago. Now that keto is on the scene and there’s a general carb phobia, you may be thinking again about going on a low-carb diet like Atkins. (Atkins and keto differ in that Atkins allows for more protein, whereas keto limits protein.)
“Like many diets, you lose weight quickly on Atkins. But it does not work long term,” says Tiberio. On the U.S. News rankings of best diets, Atkins falls near the bottom because of worries about safety and negative impact on heart health.
5. Paleo-Vegan (“Pegan”)
Fusing the popular paleo diet and taking some vegan principles, the “pegan” diet focuses on eating loads of fruits and vegetables, along with nuts and seeds, oils, no dairy or gluten, and limiting beans and grains. It’s not traditionally “vegan,” which previous research has linked to weight loss, and where you eat no animal products of any kind, as it allows for a small amount of meat.
While the pegan diet hasn’t been researched for weight loss or other benefits, it’s likely that it will help you reduce your blood sugar and triglycerides, says Tiberio.
Still, the fact remains that it’s still a restrictive diet with many rules. Translation: You might lose some weight and potentially boost your health temporarily, but chances are you won’t be able to follow this unbalanced way of eating forever. The fact of the matter is that many people struggle to maintain diets that contain a long list of off-limits foods. Those hurdles put this diet mashup on the “avoid” list for weight loss, per RDs.
Some of these findings may be surprising to you. If you are totally confused on which weight loss plan is best for your body and your lifestyle, we can help. Together we can put together a doable diet that will have a long lasting strategy, not a quick drop the weight and yoyo back result.
Set up an appointment with Rebecca today!