Every day, there seems to be a new diet trend: keto, paleo, Atkins, the Mediterranean diet, or the South Beach diet. To someone trying to lose weight or eat healthier, the choices can be overwhelming. We sat down with Jennifer Cholewka, RD, CNSC, CDCES, CDN, Metabolic Support Dietitian at The Mount Sinai Hospital, to separate myths from facts and to get some guidance as to where to start.

As I look at the wide variety of diets out there, where do I begin?

To your point, diet trends are always evolving and changing. One minute, everyone’s talking about a superfood that’s good for you, and next year, all of a sudden, that food is bad for you and “out.” We’ve seen that with eggs, coffee, fats, carbs, and all kinds of things. But the first thing to ask yourself is, “What’s my goal?” If your goal is weight loss, the answer might be different than if you’re trying to live heart-healthy.

The word “diet” isn’t a great word in the world of dietitians. People see the word “diet” and often think of a quick fix. But we should really be thinking in terms of “lifestyle” instead. Whatever diet you choose, it should be sustainable, obtainable, and reasonable within your current life.

A lot of people are attracted to some of the extreme diets, like keto, Atkins, or paleo, because they want to lose weight quickly. And you will see weight loss quickly, but it’s not something that you can maintain for your life. These diets usually restrict entire food groups, which forces your body to change the way your metabolic processes work. For example, the keto and Atkins diets restrict carbohydrates, including sugars, grains, and certain vegetables and fruits, while the paleo eliminates foods like grains and most dairy products.

Is that unhealthy?

Yes, I think it’s unhealthy. People have a tendency to “yo-yo” with these diets, or in other words, lose the weight and then regain it. Because you’re restricting entire food groups, your body can’t stay on it forever. That’s why the first thing you should think about is, “What is sustainable?”

What do you mean by “sustainable?”

Your lifestyle plays an important role in what type of diet you should follow. For example, intermittent fasting is a very popular diet lately. There are many different types of intermittent fasting, but one example would be to only eat between noon and 8 pm. For many people, that’s not possible because of their work schedule or their home life. The extreme diets we mentioned are not sustainable because they eliminate entire food groups. They force our bodies into unnatural metabolic processes, and you can’t keep it up. That’s why we need to shift our mindset from “diet” to “lifestyle.”

It’s better when a person makes small changes that are manageable and attainable. You probably shouldn’t change every aspect of your diet at once. Maybe you’ve identified that you need to stop drinking soda, decrease fast food consumption, and exercise more. Doing all three of those at once may be overwhelming and frustrating. Implement changes that are doable, and tackle those goals, one by one. And acknowledging your accomplishments is key.

So say my goal is losing weight. What’s the best diet for weight loss?

I’m not a huge fan of any one diet in particular, but if your goal is weight loss, my No. 1 recommendation continues to be Weight Watchers, which allows you to eat all kinds of foods but carefully track what you eat. It has a lot of those things that I view as very important—including balance and portion control. I feel the Weight Watchers approach is very manageable for a lot of different lifestyles. It’s doable whether you work 9-5, work nights, or travel. I find it to be a very reasonable and sustainable approach. You’re able to treat yourself if you want, but you’re encouraged to eat foods that are much healthier, such as lots of fruits and vegetables, and lean proteins. The support aspect of Weight Watchers is also very helpful for people, whether it’s going to an in-person meeting or getting connected to a coach who can help you.

The Mediterranean diet, which focuses on vegetables, fruits, whole grains, seafood, and olive oil, has a lot of pros, as well. It encourages balance; it encourages eating more whole foods; it’s low in processed foods. It also allows alcohol, which is important to some people.

The DASH diet, or Dietary Approaches to Stop Hypertension, is a diet developed through research sponsored by the National Institutes of Health. The DASH diet is similar to the Mediterranean diet and is a low-sodium diet that’s heart healthy. These three diets are almost always the top diets recommended by U.S. News & World Report. Their recommendations are updated every year and they list their top diets for different goals. That’s a good place for people to start.

And if your goal is weight loss, “calories in, calories out” is really going to drive weight loss. So portion control is critical, as is exercise. Again, make small changes that are sustainable. You won’t be able to hit the gym five days a week to start. You might try committing to walk one day a week on the treadmill for 30 minutes. Or walking instead of taking the subway. It sounds small, but you’ll see changes that last over time.

People are always going to look for ways to lose weight as fast as they can and keep it off. But there’s never going to be a quick fix for anything.

No matter what’s happening in the news, it seems a new diet is always trending or a celebrity is hawking another miracle diet. We asked Jennifer Cholewka, RD, a dietitian and Advanced Clinical Nutrition Coordinator with the Mount Sinai Health System, about the pros and cons of some of the hot new diets.

Why is there so much hype surrounding diets? Why are they such a hot trend?

Diets are always going to be a hot topic. People are always looking for ways to lose weight as fast as they can and keep it off. But there’s never going to be a quick fix.

Keto is really trending these days.

I’m not a big fan of the keto diet. Yes, you can eat a lot of vegetables. But I don’t see how a diet that encourages eating lots of butter, mayonnaise, bacon, and cheese can be healthy over the long term. Everyone I know who has tried the keto diet loses weight. But it’s not possible to keep it up very long. Ketosis is a metabolic process in which the body, when it runs out of glucose, burns stored fats and then ketone bodies, the substances your body produces while you are following these dietary restrictions.  Our bodies prefer to use carbohydrates, such as starches and sugars like glucose, as the primary substrate for energy, for brain function, and organ function. If you’re putting your body into ketosis, your body isn’t meant to live in that state over the long term. It’s not sustainable.

Ketosis helped our ancestors survive starvation mode eons ago. They couldn’t count on regular meals. People only went into ketosis when they were starving and in dire straits. And in forcing your body to shift its preferred metabolic pathway, I see nothing but trouble over the long term.

Sometimes people rely on folk wisdom with diets like the Keto and Paleo diets. They say that our bodies have not evolved along with society, and these diets are more natural since they reflect the way we were 50,000 years ago.

Yes, people often latch onto that. Paleo is a very restrictive diet. It is technically a healthy diet. It can also be high in fat, especially saturated fat. If you have cardiovascular disease, that would be an issue. That’s why it’s important to talk to a physician if you’re overweight and trying one of these diets. You might lose weight, but in eating things like nuts that are higher in saturated fats your risks might outweigh the benefits.

Why are these fad diets so popular?

People crave rules. They want restrictions. They want to be told what to eat—and what not to eat. Dieting can be overwhelming. They don’t want to have more choices. And I think that’s why some of these diets like keto and paleo are trending. It’s simple. They’re given a list of what they can have and what they can’t have. They can eat the same thing every day if they want. All that matters is that you follow the formula, whether it’s the keto formula or the paleo formula. But you can’t keep it up over time. And that’s why people yo-yo with their weight. They may lose weight, but they gain it back rather quickly, unfortunately.

People often latch onto celebrities and their diets. For instance, Kim Kardashian lost 70 pounds on the Atkins diet, along with weight training. So they say, it worked for her, I’ll do that.

People will always pay attention to celebrities and their lifestyles. They see Kim Kardashian is following some diet that’s trending. Sure, she looks great. But she also has a personal trainer that she works with six days a week. She’s also on a very restrictive diet. I’m sure she has a nutritionist or a wellness coach that’s overseeing this whole plan. And she probably has someone preparing her meals. This isn’t a lifestyle most people can follow. Because if you’re fully going to adopt the Kim Kardashian weight loss approach, it means taking on the whole package. Celebrities are always going to have more resources, guidance, and control over their lifestyle. After all, their looks are part of their career and their income. We don’t have that luxury, unfortunately.

If you don’t understand everything that you’re going to have to do—and if you have no support, no guidance, no clinical advice—it’s very unlikely that you’re going to follow that diet for very long. Also, Kim Kardashian is quite young. We don’t know what the long-term effects of restricting carbohydrates like that are for someone that young.

What about seeing a dietitian? Is that something people should do?

I think it’s always great to touch base with a dietitian—specifically a dietitian—if you’re looking to make any sustainable changes to your diet. There are many ways to connect with dietitians that don’t necessarily involve expensive private counseling fees, or even face-to-face counseling. A lot of dietitians work through online platforms like Rise, Noom, or My Fitness Pal. I encourage people to do some research. See what is easiest for you to get started and get some support through your weight loss journey or health journey.

What is the difference between a dietitian and a nutritionist?

A registered dietitian is a person who has gone through undergraduate training, an accredited internship, passed the registered dietitians exam, and met all the credentialing requirements. After their name you would see “RD.” There are no credentialing or educational requirements for nutritionists. That being said, nutritionists can certainly offer some insight or be supportive through a diet or lifestyle change. Again, I encourage people to do their research, make sure the person is qualified, and decide whether their services are a match for your goals.