Most nutritionists agree there is no one dietary pattern that’s ideal for everyone. In addition to your unique combination of genes, medical history, cultural and family background, taste preferences and daily living patterns, you apply your own set of values to your eating approach. Some people may focus on preventing or managing disease, others on protecting the environment, some on managing weight, others on enjoying what they eat and so on. Prioritizing what matters to you can help determine your eating style.
The six dietary patterns discussed here have dominated headlines over the past few years. We’ve tapped nutrition experts to share their input, based on experience and scientific evidence, about which of these diets may (or may not) be a good match for you.
Expert: Shelley Case, RD, author of Gluten Free: The Definitive Resource Guide (Case Nutrition Consulting, 2016)
What it means: Gluten is the general name for a group of proteins found in the grains wheat, rye and barley, says Case. Gluten-free diets avoid these three grains and their derivatives.
Why it’s a thing: A gluten-free diet is medically necessary for those with celiac disease (a severe, inherited autoimmune intestinal disorder) and non-celiac gluten sensitivity, which most experts believe is an inflammatory disorder. Other people adopt a gluten-free diet with hopes it will accelerate weight loss, in a quest to eat healthier or to support friends or family who need to be gluten free.
“If you don’t have celiac disease or gluten sensitivity, going gluten free is not a ‘magic bullet’ to cure everything that ails you,” warns Case. Contrary to what many believe, science does not support the diet as a healthier way to live or as a means to weight loss.
What it takes: “Regardless of whether someone has celiac disease, non-celiac gluten sensitivity or is following the diet by choice, adapting to a strict gluten-free lifestyle can be extremely challenging,” says Case. Traditional breads, pastas and the like are obviously off-limits, but a lot of unexpected products also contain gluten, such as soy sauce, many soups and gravies, bouillon cubes and more. Determining gluten-free status of products and meals takes time, and finding gluten-free foods can make traveling and social eating difficult. Lastly, gluten-free alternatives are often significantly more expensive than their counterparts, they are not required to be enriched with iron and B vitamins like foods made with wheat flour, and many are low in nutrients, often lacking in fiber and consisting largely of refined grains and empty starches.
If science doesn’t support gluten free as a means for a healthier diet or weight loss, then why would people choose it if they don’t have to? It’s likely that removing many of the high-calorie, low-nutrient, gluten-containing foods from the diet and replacing them with wholesome, nutrient-rich foods makes the pathway to healthier eating easier. However, you can do that without removing gluten.
Expert: Keri Gans, RDN, certified yoga teacher and author of The Small Change Diet (Gallery, 2011)
What it means: “The premise of the paleo diet is that we should eat like our ancestors did during the Paleolithic era as hunters and gatherers,” says Gans. This diet allows meat, poultry, fish, eggs, fruit, vegetables and healthy fats such as nuts, seeds, olive and coconut oils and avocado, while prohibiting all pulses (beans, lentils, chickpeas, peas), grains, dairy, added sugars and processed foods with artificial ingredients.
Why it’s a thing: Why people choose a paleo lifestyle varies. Some are attracted to the no-processed-food focus, while others like the trendy low-carb eating pattern. Gans recognizes that some may choose it for health reasons. The paleo diet discourages added sugars, so someone with diabetes may try it to stabilize blood sugar levels.
What it takes: “The pros of the diet are that it focuses on foods minimally or totally non-processed and encourages eating plenty of fruits and vegetables,” says Gans. “The con, though, is that it completely eliminates food groups that typically provide important nutrients.”
For example, eliminating dairy may make it harder to meet your calcium and vitamin D needs. In addition, if you’re not eating a lot of fruits and vegetables or you limit the amount of seafood on your plate, Gans says the diet might be too low in fiber and omega-3 fats, which are important for reducing heart disease risk.
If the takeaway message is to “eat plenty of meat,” Gans says, then the diet could be high in saturated fat, which may increase risk for heart disease and certain cancers.
“This diet is restrictive, and for many people the elimination of foods they love—especially bread, pasta, potatoes and rice—makes it almost impossible to stick to,” she adds.
Expert: Cynthia Sass, MPH, RD, author of Slim Down Now: Shed Pounds and Inches with Pulses–The New Superfood (HarperOne, 2016)
What it means: According to Sass, the basic premise is to eat all or predominantly plant-based foods. Vegans exclude all animal-derived foods, while vegetarians allow some—typically dairy and eggs. Others may limit meat, fish and poultry. As long as fruits, vegetables, whole grains, pulses, nuts and seeds are the mainstay of the diet, it’s plant-based.
Why it’s a thing: People value plant-based eating for many reasons, including religious beliefs, animal welfare, concern for the environment, protection against chronic disease or a combination of these factors.
What it takes: “In my opinion, everyone can benefit from a predominantly plant-based diet, as long as it’s whole-foods based and there is adequate planning to ensure that nutrient needs are met,” says Sass. Nutrients to keep an eye on include protein, iron, vitamin B12, calcium, zinc, vitamin D, iodine and omega-3 fatty acids.
Sass stresses whole foods because she has seen many people adopt vegan or vegetarian diets consisting mostly of processed foods, with few to no servings of fresh produce, whole grains, pulses, nuts and seeds. “With the popularity of veganism, it’s very easy to find vegan versions of nearly any food, from doughnuts to pizza, bacon, ice cream and cheese,” she says. Just because a food is vegan doesn’t mean it’s healthy.
When whole foods are the focus, benefits include greater intake of dietary fiber, vitamins, minerals and antioxidants; better gut health; and a reduced risk of obesity, heart disease, cancer, high blood pressure and type 2 diabetes. Plus, the production of plant-based foods uses fewer natural resources and emits fewer greenhouse gases into the environment.
Expert: Bonnie Taub-Dix, RDN, author of Read It Before You Eat It (Plume, 2010) and creator of BetterThanDieting.com
What it means: The Mediterranean diet calls for fresh produce, healthy fats (like nuts, seeds and olive oil), whole grains, fish, lean dairy and even red wine, says Taub-Dix.
Why it’s a thing: This eating approach isn’t so much a plan as it is a lifestyle of eating together with your family, cooking foods that are wholesome and real and appreciating all that good health brings, Taub-Dix says. “The Mediterranean diet reflects cooking with a heart and a history of those who came before us and how they ate,” she says.
The diet became popular based on research showing that people living in Mediterranean countries—like Italy and Greece—had lower risk than Americans for many chronic diseases, including heart disease and type 2 diabetes. The research suggests eating poultry and eggs in moderation and eating red meat rarely. It limits processed meats, refined grains, added sugars and refined oils.
What it takes: “Foods that don’t wear food labels, like fruits and vegetables, should take up at least half of your plate and, for foods bearing labels, choose those that have short, recognizable ingredient lists,” Taub-Dix says.
“As with any other sensible diet, keep proper portions in mind,” she adds. “Olive oil weighs in at 2,000 calories per cup, so even though it has been the staple of the Mediterranean diet for ages, you still shouldn’t eat it as if it were soup.”
Expert: Jill Weisenberger, RDN, author of Diabetes Weight Loss: Week by Week (American Diabetes Association, 2012)
What it means: The acronym DASH—short for Dietary Approaches to Stop Hypertension—explains the purpose of this popular diet. “DASH was created and studied as a way to reduce high blood pressure,” says Weisenberger. “Researchers included foods [with nutrients] beneficial for blood pressure and limited those suspected as harmful to blood pressure.”
Why it’s a thing: This diet attracts those trying to lower their blood pressure and “anyone who wants a balanced plan based around everyday foods and without a list of strict rules.” Since the initial studies, “DASH has also been linked to less type 2 diabetes, better heart health and smaller waist sizes,” she adds.
What it takes: Encouraged foods include fruits and vegetables, low-fat dairy, whole grains, fish, poultry, legumes, nuts and vegetable oils. The diet recommends limiting foods high in saturated and trans fats, added sugars or sodium. It limits sodium intake to 2,300 mg; some, such as those 65 and older, may benefit from going as low as 1,500 mg per day.
The diet was not designed for weight loss purposes, but, if that’s a goal, Weisenberger says, then create portion-size and calorie budgets to meet your needs. Although no foods are off limits, certain foods can be limited to meet goals; these include fatty meats like sausage and prime rib, coconut oil and other tropical oils, full-fat dairy products and added sugars from foods such as pastries and sugar-sweetened beverages.
Expert: Karen Ansel, RDN, CDN, author of Healing Superfoods for Anti-Aging (Hearst, 2017).
What it means: Intermittent fasting is a dietary pattern that encourages fasting for certain periods of time throughout the week.
Why it’s a thing: According to Ansel, this approach is attractive primarily to people who want to lose weight. The premise is that fasting can lower blood sugar, improve hormones that aid in weight loss and burn more fat. Also, a 2017 animal study in Ageing Research Reviews shows its “profound beneficial effects” on many health markers, including age-related disease processes such as dementia.
What it takes: There are variations on the amount of time you spend eating and fasting with this dietary pattern. Some adherents fast for 16 hours out of the day and eat during the remaining 8. Others do a 24-hour fast a couple of days a week, while still others eat fewer calories—about 500 to 600—two days a week and eat as much and whatever they want on all other days.
A few studies have indicated intermittent fasting can help with weight loss. Ansel says that more research needs to be done before recommending it.
“The main drawback is that the intermittent fasting diet doesn’t give you any guidance regarding the foods you eat, so when you are eating you could technically be loading up on less-than-healthful foods,” says Ansel. “So if you’re eating junk food on your cheat days, you could be missing out on a lot of nutrients, and over time you could really be hurting your health. If you’re the type of person who needs a lot of structure, this plan could really backfire.”
Animals and humans evolved in food-scarce settings, so intermittent fasting isn’t new. Still, Ansel stresses mixed study results, adding that “it might theoretically help somebody who is trying to get in touch with their feelings of satiety and fullness, as it promotes both of these to the extreme.”