Looking to Lose Weight in 2019? Here’s the Skinny on the Hottest Fad Diets

If you’re looking to shed some weight in the new year, join the crowd. Roughly 45 million Americans embark on a new diet every year, many of whom begin shortly after the ball drops. And while there’s a plethora of types of diets to choose from, you might be wondering: Do any of them work?

Elimination diets are particularly trendy right now, says Gillian Arathuzik, a registered dietitian at the Lifestyle Management Institute at Lahey Outpatient Center, Danvers. What diets work, what diets encourage healthy eating habits, and which ones are most sustainable?


The ketogenic diet — also called the keto diet — is a very low-carb, high-fat diet. By restricting your carbohydrate intake, the diet deprives you of glucose, your body’s typical energy source. Your body turns to fat for fuel, and breaks it down to produce ketones as a source of energy. This puts you into a metabolic state called ketosis, during which your body becomes efficient at burning fat.

“This saved us in times of starvation back in caveman days,” Arathuzik said. “You lose a dramatic amount of weight, partly because you’re eating so much less, and weight loss is typically driven by calorie reduction, but you also lose a dramatic amount of water weight and you’re breaking fat down.”

Arathuzik says that keto is a risky diet for those with diabetes, as a high ketone level paired with a low insulin level can lead to a potentially fatal condition called diabetic ketoacidosis. For everyone else, the diet is generally safe, but it can be very challenging to stick with.

“It’s ridiculously restrictive and hard to sustain,” she added, “and there’s a lot of controversy about whether the carbohydrate limit — typically under 40 grams a day — is too low.”


Whole30 is an elimination diet designed to help you understand how certain foods affect your body, mood and energy levels. It requires you to strip your diet down to the bare essentials, and, after 30 days, you slowly start reintroducing foods. Your body’s reaction to those foods tells you which are OK to eat, and which you should keep avoiding.

Whole30 isn’t explicitly designed for weight loss, Arathuzik says.

“However, most people try to keep it going for as long as they can to lose weight,” she said. “If you cut out a disturbing portion of the food supply, you’ll obviously lose weight.

Whole30’s not very easy to follow, though, as it’s an extremely rigid and restrictive diet.

“Technically, you could follow it forever and not be nutrient-deficient, but it would be hard to actually socialize and be normal,” Arathuzik said. “And it’s not based on any science.”


The paleo diet limits you to foods that can ostensibly be obtained through hunting and gathering: lean meats, fish, fruits, vegetables, nuts, seeds. Foods that require farming or processing, such as dairy, legumes and grains, are gone.

“The irony of the paleo diet is that these foods are not really how cavemen ate, but you do lose weight,” Arathuzik said. “Sometimes people want to be told, ‘You can eat this, but you can’t eat that.’ Paleo is very black-and-white, and it’s another low-carb diet. It eliminates some healthy foods, but it wouldn’t cause any major nutrient deficiencies. It’s less restrictive than keto, but it can still be very hard to sustain.”


TB12 is a diet and fitness plan created by Tom Brady, the NFL’s oldest quarterback. At 41 years old, Brady is still in great shape and shares his longevity secrets in his book, “The TB12 Method,” and on his website. His diet mostly comprises plants and lean proteins, and it restricts a long list of foods. There’s no dairy, white flour, white sugar, tomatoes, peppers, mushrooms, alcohol or caffeine.

Arathuzik isn’t sold.

“It’s another ridiculously restrictive diet that’s not based on science,” she said. “He won’t even let people drink coffee. None of these other diets restrict coffee.”

Do Any of Them Work?

While these low-carb, elimination types of diets will be effective in helping you lose weight in the new year, Arathuzik says that none of them are sustainable.

“The minute people go off, they regain most, if not all, the weight, and potentially more,” she said. “Unless you can truly live like this forever, it’s very challenging to sustain the weight loss once you start incorporating back in carbohydrate foods.”

For a more sustainable route, she recommends either the DASH Diet or the Mediterranean Diet, which can help you lose weight and build healthy eating habits in the process.

“Both have been well-proven in large research studies to be successful, not just with weight loss but in helping people to reduce inflammatory markers and improve their health and either manage or prevent disease.”

For weight loss guidance and support, Arathuzik suggests a community weight-loss program, like Weight Watchers, or a medical weight loss center.

“The advantage of medical weight loss is that you have access to a multidisciplinary team of physicians, dietitians and social workers. Your physician can also prescribe an FDA-approved weight-loss medication and refer you for surgical weight loss if that’s a good option for you.”

The most important thing to keep in mind when considering a new diet, Arathuzik says, is to pick one that sets you up for success.

“The best diet for you is the one you will follow,” she said, “and can continue to follow long-term.”


*The content on this website is for informational purposes only and is not medical advice. Please consult a physician regarding your specific medical condition, diagnosis and/or treatment.

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