Diet fads tend to come and go. Will the same hold true for the most popular diets of 2019?
Losing weight or “eating better” on your mind these days? There is no shortage of diets grappling for your attention. And the reality is that most diets — the good and bad — will help you lose weight in the short term. But the difference is in keeping it off, and that relies on having a doable plan that you can stick with for life. Usually this means that diets that cut out entire food groups (sorry, keto) or impose strict rules for eating (looking at you, intermittent fasting or Whole30) are out unless medically advised by your healthcare team.
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 Diets to Consider Trying in 2019
1. Mediterranean Diet
U.S. News & World Report just ranked this mostly plant-based eating approach its No. 1 overall diet, 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.
Even better 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, supports heart and brain health — and your waistline. “We also know from research that this eating style can help with weight loss,” she says. 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.
2. WW (Formerly Weight Watchers)
You know it by its previous name: Weight Watchers. 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. Boosting your health may be another, 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, however: If you have a personal history of eating disorders, you may want to sidestep this approach. A 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. Flexitarian wins for its flexibility. “Diets don’t have to be all-or-nothing,” says Tiberio. Cutting down meat consumption is generally a positive; one review of 25 studies, published in December 2016 in the journal Frontiers in Nutrition, found that semi-vegetarian diets were associated with weight loss, lower blood pressure, and a reduced risk of type 2 diabetes. The authors concluded that though it’s a popular eating approach with women, men, too, can benefit — especially because guys generally consume more meat.
1 Diet That Lands in the Middle: Intermittent Fasting, or IF
Intermittent fasting (or IF) involves extended periods of not eating, and there are several ways to approach 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 and 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.
Top 5 Worst Fad Diets for 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. Don’t even think about it. “This is not a healthy or sustainable diet, and there are healthier ways to lose weight,” says Gorin. “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,” she says. That includes things like fruits and vegetables. Bottom line: Don’t even try this diet.
There’s nothing wrong with the foods that Whole30 asks you to eat, like vegetables and sweet potatoes. But it’s dripping with rules that you are not to cross for whatever reason: no added sugar, alcohol, grains, legumes, dairy. And while you don’t need dairy and grains to be a healthy person, it can create a cycle of guilt around food, says Anne Mauney, MPH, a registered dietitian based in Washington, DC. Once you’re off the program, 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, or trying to be ‘good,’” she says. That’s no way to live.
3. Keto Diet
While there is emerging interest from the medical community in using this diet, a high-fat, moderate-protein, very-low-carb plan, as adjunct treatment for various health conditions (and it can stimulate weight loss quickly), long-term studies are needed on the weight loss and health benefits of keto, 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. Well-planned versions of keto could be healthful. On the other hand, “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.
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,” where you eat no animal products of any kind, since it allows for a small amount of meat. These are all healthful foods and it’s likely that it will help you reduce your blood sugar and triglycerides, says Tiberio. But the fact remains that it’s still a restrictive diet with many rules. And oftentimes people struggle to maintain diets that contain a long list of off-limits foods. Those two factors put this diet mashup on the “avoid” list, per RDs.