If there are two words that can make nutrition experts everywhere roll their collective eyes, they would be "keto diet." Sure, it's wildly popular, promises shocking weight loss results, and has even been promoted by some of our favorite celebrities (we're looking at you, Halle Berry). But is it actually healthy?
Most experts will say the answer is a big, fat no—and unfortunately, keto is not the only wolf in sheep's clothing when it comes to faux health food trends. This year, we saw the rise of several other popular approaches to losing weight that all claim to be "healthy" but fall way short on actual evidence, science, or even good judgment.
We asked several experts to round up the best of 2019's worst, a.k.a. the health food trends that are decidedly unhealthy (and hopefully primed to fade away in 2020).
Let's get this one out of the way first. Keto, a low-carb, high-fat diet that was originally designed for people with epilepsy, can be beneficial in the context of its medical application. But somewhere along the way, people started doing keto just to lose weight—and that's not great.
"The number one problem with keto is that is is not designed to be a sustainable approach to being healthy—it's about weight loss, period," says Barbie Boules, RDN of Barbie Boules Longevity Nutrition. "So what are you supposed to do when it's time to stop?"
What's worse, when you're on the keto diet you aren't just cutting back carbs; you're also cutting out valuable nutrients that carbohydrate foods provide, like magnesium, potassium, and B vitamins. "The keto diet limits what you're eating and because of this, you may be at risk for many nutritional deficiencies," says Amy Gorin, MS, RDN, owner of Amy Gorin Nutrition in the New York City area. "It's also a dangerous diet for people with type 1 diabetes [since] the eating style increases the risk of diabetic ketoacidosis, a life-threatening condition."
Proponents of this trend claim that carb cycling (i.e. increasing and decreasing your levels of carb intake from day to day), can reset your metabolism and help you maintain a healthy weight.
But Boules stresses that carb cycling is designed for competitive athletes, so unless that's you, you're not likely to see any benefit. In fact, you might actually feel pretty terrible. "My specialty is women's wellness: being this imbalanced from day to day in terms of a macronutrient spread can create hormonal hell," explains Boules.
Nutrition experts have been warning people forever about the dangers of treating your diet like a yo-yo, and that's essentially what you're doing here with carbs. Habits you can stick to consistently are always a better choice.
Keto and vegetarian, vegetarian and intermittent fasting, intermittent fasting and keto: as long as two diets weren't diametrically opposed to one another, people were putting them together in 2019. Hey, if one diet helps you lose weight, it stands to reason that two diets will help you lose even more, right?
Wrong. "Trying to follow a meal plan that is both keto and intermittent fasting (or vegan and keto, etcetera) can be incredibly limiting and unlikely to be sustained long-term," says Erin Palinski-Wade, RD, author of Belly Fat For Dummies. "[If you] try to make too many changes at once, you may end up making no changes at all."
Plus, matchmaking the latest diet trends can cause serious nutritional deficits. Palinski-Wade says that getting enough protein in a healthy way on a keto diet is difficult enough on its own, but add to that following a vegetarian or vegan diet (in which protein sources tend to have less protein and more carbohydrates) and you're making it very difficult to stick to this eating style.
Bottom line? One diet at a time, please.
In the summer of 2019, Burger King introduced America to the Impossible WHOPPER: a meatless alternative to the classic patty that's been served at BK since, well, forever. The plant-based burger is made from water, soy-protein concentrate, coconut oil, and sunflower oil. It even "bleeds" like a regular burger thanks to something called heme.
The problem, though, is the overall quality of processed, plant-based foods. "Adding more plant-based foods to your diet is a terrific way to improve overall health, but not all plant-based foods are equal," says Palinski-Wade.
Whether it's plant-based burgers or KFC's "chicken" nuggets, many of these fast-food alternatives are high in sodium and saturated fat, meaning their claims of being the healthier option are typically less than accurate. For example, BK's Impossible WHOPPER contains 630 calories, 11 grams of saturated fat, and 1,080 grams of sodium; by comparison, a regular ol' WHOPPER comes in at 660 calories, 12 grams of saturated fat, and 980 grams of sodium.
Premade Cauliflower Crust
If you're buying a frozen cauliflower crust for Friday pizza night and patting yourself on the back for making the healthier choice, we have some bad news for you: you should have just stuck with the carbs.
"Most commercial cauliflower crusts are no 'cleaner' or healthier than a crust made from wheat, yeast, water, and salt," says Boules. "They may be lower in carbs, but people need to be better educated about why 'low-carb' is not [always] a healthier approach to eating—especially when it means making up for texture and flavor with nutritional garbage."
What "nutritional garbage" is Boules referring to? Unnecessary ingredients like xanthan gum, corn or rice flour, and added sugar, which can be found in many of the cauliflower crusts sitting in your local frozen food aisle. If you want to reap the health benefits of a cauliflower crust, take the time to make your own.
Otherwise known as the "Dietary Approaches to Stop Hypertension" diet, this style of eating has been promoted by the National Heart, Lung, and Blood Institute as a way of lowering blood pressure without medication. The DASH diet encourages people to eat whole grains, fruits, vegetables, and low-fat dairy products, along with small amounts of fish, poultry, red meat, legumes, and fats.
The only problem? It wasn't designed for weight loss, so all that dairy, grain, and starch turned out to be not so great for people wanting to slim down. Since then, the diet continues to be revamped and revised several different ways with an eye toward weight loss, but Cynthia Thurlow, NP, a nurse practitioner specializing in nutrition, is still not impressed.
"This one has largely been discredited [because those foods can be] highly inflammatory and contribute to weight gain, diabetes, and obesity," she says. "There were limited studies on its efficacy and I feel that it's an outdated option."
If you've ever browsed keto recipes on Pinterest, you've probably noticed a lot of them including something called MCT oil. There's a lot of complicated science here, so we'll just cut to the chase: MCT stands for medium-chain triglyceride, a fatty acid chain found naturally in certain oils. MCT oil is a manufactured substance that became popular with the rise of bulletproof coffee. Its fans say the supplement can burn fat, suppress hunger, and support weight loss, especially when used in conjunction with a low-carb, high-fat diet like keto.
Sounds good, right? Not so fast. Palinski-Wade says that much of the research was performed on small populations, so it may not apply to your own individual health needs. What's more, it could do more harm than good if you're not judicious with it. "Depending on your individual dietary needs, adding large amounts of this oil to your meals and drinks may not benefit your health," warns Palinski-Wade. "It can provide an excessive amount of calories and large amounts can cause bloat or discomfort."
Hemp-derived CBD oil (a.k.a. cannabidiol, an active ingredient in marijuana) is pretty much everywhere right now, being touted as a natural treatment for symptoms of anxiety, depression, insomnia, and chronic pain. Per Harvard Health, the substance doesn't cause a high, so people have started supplementing with it left and right, even going so far as buying CBD-infused coffees from specialty retailers.
While some of the research on CBD oil looks promising, it bears repeating that it's a supplement—and supplements are generally not regulated by the FDA, so it's kind of a wild world out there. It's convenient to get your daily dose of CBD with your morning cup of joe, but the potency and purity of your supplement could vary greatly from one purchase to the next.
"If you are choosing drinks and coffees with CBD added, make sure you know what you are getting," advises Palinski-Wade. "And make sure to discuss taking CBD with your healthcare professional to ensure it is appropriate for you and won't interact with any other medications or supplements you may be taking."
At the end of the day, CBD oil could do everything it claims to do—but those claims haven't been proven yet, don't assume you've got a free pass here.
The evidence isn't quite there yet for intermittent fasting benefits and some people can take it too far. "Intermittent fasting can be done in a way that's healthy and sustainable, but I've talked with many people who are following the eating style and taking in way too little to sustain an active lifestyle," says Gorin.
Even though it can work in moderation, intermittent fasting also comes with a "Do Not Try" warning for a lot of different people. Gorin says that because it's restrictive in nature, intermittent fasting could lead to overeating or binging, making it a potentially harmful choice for people with a history of disordered eating.
It's also not a good choice for people with diabetes, children, or women who are pregnant or breastfeeding. It's tough for people who travel a lot or who have unpredictable schedules. And finally, it can pose a problem for athletes (or anyone who likes to hit the treadmill in the a.m.). "I don't like that people are often working out in the morning without any fuel," says Boules. "That's a no-no."
Chia Seed Everything
These teensy little seeds have had a huge cultural impact on American dieters in the last year or so, popping up in smoothies, yogurt, and salads, and even snagging the starring role in their own dish: chia seed pudding. High in fiber and omega-3s, chia seeds pack a big punch in a small package.
Though the research on the benefits of eating chia seeds is still emerging, there's some evidence that they may also lower cholesterol and blood pressure. So why are they on this list? "I think chia seeds are a nice, healthy fat option, but to consume them daily—or as a dessert substitute—is not necessary, and I see far too many people using chia seed pudding as a 'safer' daily dessert option," explains Thurlow.
Instead of stuffing your face with flavored chia seed pudding and thinking it's better than treating yourself to a reasonable dish of ice cream, consume chia seeds in moderation rather than in excess (and, by all means, let yourself have a real sundae once in a while).