Every year, there’s a new crop of diets focused on weight loss, disease prevention, or overall longevity. In general, the best of these avoid calorie counting, focus on whole foods, and are either balanced enough that they can be followed for the long run, or effective enough that they’re worth trying for a short time. Here’s a look at five of today’s most popular eating plans, with the best and worst of each.
1. The Ketogenic Diet
Possibly the most popular diet of 2018, the ketogenic (also called “Keto”) diet focuses on minimal carbs—about 5 percent of daily calories—with moderate protein (20 percent) and very high amounts of fat (75 percent). It’s designed to shift the metabolism into ketosis, a state in which the body burns fat, instead of sugar, for fuel. The diet is geared primarily for weight loss, and studies show that it may also prevent seizures and protect against neurodegenerative disorders and other diseases.
What you eat. The Keto diet is composed mostly of “good” fats—coconut oil, nuts, full-fat dairy, and other forms of saturated and monounsaturated fats. Hydrogenated fats and processed vegetables oils such as safflower or soybean oils are avoided. Proteins include meat, eggs, fish, and nuts. Vegetables are limited to low-starch varieties, and fruit is generally restricted to berries. Beans, grains, sugars, or starches are avoided.
What’s good. Because it strictly bans sugar and starches, it can promote balanced blood sugar and rapid weight loss. And the high amount of fat means you’ll rarely feel hungry.
What’s bad. It’s low in fiber, and limits fruits, vegetables, and legumes—foods that have been shown to protect against cancer and other diseases. It’s high in saturated fats, which have been linked with increased risk of disease. And there are side effects, including dehydration and what’s called “keto flu,” a feeling of lethargy, brain fog, and nausea.
The bottom line. The Keto diet is great for quick weight loss and balancing insulin, but it’s generally not a life-long eating plan.
2. Intermittent Fasting
This plan involves cycling between periods of eating and fasting. The most popular approach, called the 16/8 plan, limits eating to an eight-hour window. So, for example, you’d finish eating at 8 p.m., and then have your next meal at noon the following day. Other plans avoid food for one or two days a week, while eating normally on the remaining days. Some studies show that intermittent fasting can promote weight loss, decrease insulin resistance, improve metabolic health, protect against disease, and possibly increase longevity.
What you eat. Generally, whatever you want. There are no caloric recommendations, nor any restrictions on the kind of food you eat. In reality, most people who follow this plan focus on healthy foods.
What’s good. It’s relatively easy to follow, and allows for the consumption of a wide variety of healthy foods. It’s also extremely flexible, unlike other diets, and can accommodate specific eating plans including vegan, vegetarian, low-carb, and diets based around allergies or food sensitivities,
What’s bad. Because there are no guidelines, you may be tempted to overeat or binge on unhealthy foods—especially if you haven’t eaten for 16 hours. It’s also easy to get dehydrated.
The bottom line. You can use Intermittent Fasting on a regular basis, but only if you don’t have trouble sticking to a healthy eating plan.
3. The Alkaline Diet
Designed to create an alkaline state in the body, this diet—recently popularized by Patriots quarterback Tom Brady—avoids high-acid foods and encourages the consumption of alkaline foods. The goal of the Alkaline Diet is to promote optimal pH of blood and cellular fluids—around 7.2 to 7.4, or slightly alkaline. It’s thought that chronically acidic blood leads to weight gain and a variety of health issues, and that an alkaline diet can reduce the risk of Alzheimer’s, osteoporosis, kidney disease, joint inflammation, rheumatoid arthritis, and even cancer.
What you eat. Fruits, vegetables, and some nuts, legumes, and grains are considered alkaline in varying degrees. The diet avoids high-acid foods such as meat, dairy, eggs, fish, sugar, alcohol, processed foods, and grains including wheat, white rice, and rye. Generally, about 80 percent of the diet should be alkalizing foods, with 20 percent acid-forming.
What’s good. The diet focuses on whole foods and includes ample amounts of vegetables and fruits, as well as specific nuts, grains, and legumes, all of which have been shown to promote health and reduce the risk of disease. It doesn’t eliminate entire food groups, and is flexible enough for vegans or vegetarians.
What’s bad. It’s complicated to follow. You’ll generally need some kind of chart or reference to figure out which foods are acidic and which are alkaline, and even experts on
the topic may disagree. It also tends to be low in protein.
The bottom line. If you make sure that you’re getting enough protein, and can get used to following charts and lists, the Alkaline Diet can be a long-term eating plan.
4. The Whole30
Based on the principles of the Paleo diet, the Whole30 goes one step further and restricts the diet to whole, unprocessed foods for 30 days. The goal is not only to lose weight, but also to address health issues, especially digestive issues, gut problems, inflammation, and chronic pain. There’s no calorie counting, and the creators of the diet recommend that followers avoid weighing or measuring themselves during the 30 days.
What you eat. The Whole30 focuses on moderate portions of meat, seafood, and eggs, lots of vegetables, small servings of fruits, and healthy, unprocessed fats such as nuts, avocados, and olive oil. Sugar of any kind—including honey, coconut sugar, or maple syrup, which are generally allowed on the Paleo diet—is prohibited. Grains, legumes, dairy, alcohol, and processed foods (including “Paleo-friendly” snacks) are also avoided.
What’s good. The diet includes a variety of high-fiber, antioxidant-rich vegetables shown to reduce the risk of many diseases. Because it avoids sugars and processed foods, it can help curb cravings, break processed-food habits, promote weight loss, and balance insulin levels. The variety of foods makes it somewhat easier to follow than the Keto or other more restrictive diets.
What’s bad. Beans and legumes, shown to reduce the risk of heart disease, cancer, and other diseases, are eliminated. Dairy—which has been linked in many studies to reduced waist circumference and protection against disease—is eliminated. And there are no restrictions on saturated fats.
The bottom line. The Whole30 is a great jump start for 30 days, but if followed to the letter, it’s probably not a life-long plan.
5. The MIND Diet
A blend of two clinically proven diets—the Mediterranean Diet and the DASH Diet—this plan was developed by a nutritional epidemiologist to protect the brain and reduce the risk of Alzheimer’s disease and cognitive decline. Some studies show that it can reduce the risk of Alzheimer’s by up to 53 percent. Though the MIND Diet wasn’t designed for weight loss, it’s possible you’ll lose weight because it avoids sugar, fried foods, and processed foods.
What you eat. The diet focuses on 10 brain-healthy food groups—leafy greens, other vegetables, berries, nuts, olive oil, whole grains, legumes, fish, poultry, and wine—and avoids red meat, butter and margarine, sugary foods, fried foods, and fast food. Eggs, dairy, and fruits besides berries are neither included nor excluded, though the authors recommend that if you do eat dairy, stick with low-fat versions.
What’s good. Because the MIND Diet emphasizes leafy greens, vegetables, and legumes, it’s high in fiber, antioxidants, and other compounds shown to prevent disease. It’s also flexible enough that vegans or people with specific food restrictions can follow it.
What’s bad. The plan itself includes specific amounts of the 10 brain-healthy foods, so it involves a fair amount of planning and organization. And if you’re not a wine drinker, you’ll completely exclude one of the 10 groups. (The creators of the diet say that if you don’t currently drink alcohol, don’t start.)
The bottom line. Once you get used to organizing and planning around the food groups, the MIND Diet can be followed indefinitely.