Paleo. Mediterranean. Vegetarian. High-protein. Low-carb. Gluten-free. Low-glycemic. Intermittent fasting. Organic. Probiotic. DASH. MIND. Detox.


If you want to eat in a healthier way to prevent or cure health problems, you have a dizzying number of choices. Unfortunately, those choices are confusing—and conflicting.

The truth is, no one diet is perfect for everyone. Some people have specific food sensitivities and respond well when they eliminate their “trigger” foods, while others do fine on a wide variety of healthy foods. Some thrive on moderate portions of high-carb whole foods, while others really need a low-carb approach. And so on.

What we really need are core principles for a healthy diet—and then ways to tailor them to our personal health needs. That is exactly what the Institute for Functional Medicine (IFM)—an organization that trains health professionals to treat the underlying causes of diseases—has developed. In a heroic attempt to bring clarity to the dietary “Tower of Babel,” the IFM interviewed nutrition-oriented physicians, health-care practitioners and nutrition researchers and crossed-referenced the results with the scientific literature.

The good news: The IFM’s Core Food Plan fits just about any healthy person’s needs and is very customizable—in fact, it’s designed to be customized. Read on to get the details of a healthy eating pattern that’s good for nearly everyone—and ways you can work with a health professional to get it tailored for you.


Why do we need a new way to eat? It’s because in our society today, to a large extent, we don’t eat real food. It’s that simple. Add in our sedentary lifestyles, polluted environment and lack of sufficient sleep, and it’s no wonder so many of us have high blood pressure, heart disease, diabetes, headaches and other chronic pain, chronic infections and too much body fat.

To break this cycle, the IFM’s Core Food Plan can be a good place to start. IFM’s director of medical education, Kristi Hughes, ND, emphasizes that it’s not necessarily better than other well-established evidence-based dietary plans such as the Mediterranean Diet. Indeed, it derives some of its principles from that approach (as well as from Paleo). But the beauty of the Core Food Plan is that it provides dietary guidance that can be easily tailored to individual needs. And it does go a step beyond the official US dietary guidelines. For example, research suggests that consumption of high-glycemic grains and low-fat dairy, which are promoted by the US dietary guidelines, are not consistent with overall health. In contrast to those guidelines and most conventional nutrition advice, the IFM Core Food Plan emphasizes fresh whole foods with high phytonutrient diversity.

Nutritionist Mary Willis, RD, CDE, who helped develop the Core Food Plan, says the challenge was to create a healthy eating plan that would help transition people away from the standard American diet (or what nutritionists fittingly call “SAD”). One key problem with SAD is the preponderance of highly-refined carbs with little or no nutritional value. Many people transitioning from SAD are consuming more than 50% of their calories from carbs, Willis says, and most of those carbs are refined carbs from sugar and grains, not from vegetable or fruit sources.

The Core Food Plan, in contrast, is a balanced “plant-dominant” approach. It does include meat (if you want it to.) But you can still think of Core as everything SAD isn’t—high in vegetables (and fruits) from across the rainbow spectrum…low or moderately low in grain-based carbohydrates…low in sugar…and devoid of processed foods.


The Core Food Plan is not a deprivation diet—in fact, it’s actually pretty balanced when it comes to protein (25% of calories), fat (30%) and carbohydrates (45%). That all comes from nine distinct food groups (listed below). The appropriate servings are based on calorie needs and therapeutic considerations. To get an idea of what’s included, consider the recommendations for the 1,800-to-2,200 calorie range, which is appropriate for an average man or a woman who is physically active. Here’s what you would eat each day…

• Proteins. Seven or eight small “portions.” This category, which includes animal and plant protein, is measured in “portions” rather than “servings.” Each portion is small—just one ounce of meat, fish or poultry, one egg or one-half ounce of hard cheese, for example—but you can mix-and-match sources and have multiple portions at a meal. (A four-ounce filet mignon, for example, would be four portions.) The plan stresses “clean” sources of animal protein—lean, free-range, grass-fed, wild-caught. It can also be tailored to vegetarians—and vegans—with portions such as one ounce of tempeh or two ounces of firm tofu. According to nutritionist Willis, when you eat your protein is an important factor. In her 30 years of clinical experience, she has found that Americans do not eat enough high-quality protein at breakfast and/or lunch—and then overeat protein at dinner.

• Legumes. Two or three servings. One-half cup of cooked beans or lentils is one serving, so the total is one to one-and-a-half cups a day. Vegetarians and vegans, however, may want to increase their daily servings of legumes as a substitute for animal protein.

Dairy and dairy alternatives. Three servings. Fermented dairy foods such as yogurt and kefir are emphasized over, say, milk, as they feed the “good” bacteria in the gut, which in turn help turn down inflammation, explains Dr. Hughes. Nondairy alternatives such as almond and soy milk are also encouraged. One serving is eight ounces of milk or six ounces of Greek yogurt. In the Core Food Plan, “dairy” doesn’t include cheese, which is in the protein category.

Nuts and seeds. Three to five snack-sized servings. Examples: 10 peanuts, six almonds, one tablespoon of sunflower seeds or one-half tablespoon of nut butter would each be considered one serving.

Fats and oils. Four to five small servings. Examples: One teaspoon of butter or olive oil or two tablespoons of an oily food, such as avocado (one-eighth whole fruit). If you eat butter—which is considered a fat rather than a dairy food—choose butter made from the milk of grass-fed cows, which has a healthier balance of fats.

• Nonstarchy vegetables. 10 servings. Example: One-half cup of cooked broccoli or spinach or one cup of salad greens. This is a big increase in veggies for many people. “Most Americans get only two to four servings a day—and most are fried,” says Dr. Hughes.

• Starchy vegetables. One or two servings. Examples: One cup of cooked squash or one-half a medium potato.

• Fruit. Two or three servings. Examples: One small apple, three-quarter cup of blueberries, one cup of melon. Including fruit in your diet provides antioxidants, fiber and key vitamins. The fiber blunts the body’s response to sugar, so whole fruit, compared with foods with added sugars, is a lower-glycemic source of natural sweetness.

• Grains. Two servings. Examples: One-third cup of cooked rice, one slice of bread. “Grains are de-emphasized in the IFM food plans,” says Willis. Why? “To make room for a robust amount of colorful plant foods from other food categories that are overlooked in the grain-dominant standard American diet. Americans put a bun or wrap or breading on everything!” For people who need to avoid gluten, the IFM plan also includes many gluten-free grain picks including oats, quinoa, rice and millet.

The core plan emphasizes organic foods to reduce exposure to pesticides. It can be tailored to accommodate people who are avoiding gluten, dairy or animal foods. It can be customized for athletes, who may, for example, need extra protein. It can also be tailored for people who want to experiment with “intermittent fasting,” which calls for certain very low-calorie days followed by normal eating days as a way to improve body composition, enhance metabolism and control weight.

Some people lose weight on the IFM Core Food Plan, but that’s not the primary goal—or even the best measure of success. Rather, the emphasis is on improving health and maintaining a healthy way of eating for life. A person who transitions from SAD to Core can expect to have more energy, which in turn may motivate him or her to get more physically active. Those lifestyle changes could then lead to improvements in metabolic fitness and a reduced risk for chronic disease. Clinically, adds Dr. Hughes, patients who switch to this eating style often report more focus and concentration, enhanced sleep, greater daily stamina and an improved sense of well-being.


While adopting the Core Food Plan itself would bring a world of improvement for many people, the IFM also has developed other plans to allow health professionals—including MDs, osteopaths, naturopaths, nutritionists, nurse practitioners and others—to help patients with specific, identified needs.

Some IFM plans are “first step” diets, while others are more advanced interventions for people with certain medical conditions. Some are designed to be short-term. As the IFM practitioner’s guide states, “Nutritional and dietary needs may change or evolve as a patient moves through a layered healing process.”

The first step interventions are…

Cardiometabolic Food Plan: This is for people with cardiovascular and blood sugar–related issues such as insulin resistance and the problems that often go with them, including unhealthy cholesterol ratios, excess abdominal fat and high levels of inflammation. It emphasizes low-glycemic foods (which help keep blood sugar stable), increased fiber, meal timing and ideal serving sizes. Compared with the Core Food Plan, the macronutrient balance is slightly lower in carbohydrates and higher in protein—30% protein…30% fat…40% carbs.

Elimination Diet: Pinpointing the foods causing food allergies, intolerances or sensitivities and eliminating them (and eventually reintroducing some) is the goal. According to the practitioner’s guide, “Often, symptoms that have failed to respond to conventional medical therapy will resolve by following an elimination diet. After the initial period of eliminating foods, many chronic symptoms should improve or disappear.”

One example of an advanced intervention is the Detox Food Plan, which builds on the Elimination Diet by eliminating certain trigger foods but then goes a step further by emphasizing avoidance of environmental toxins (in plastics for example), consumption of organic foods and consumption of specific therapeutic foods that support the gut, liver and kidneys. These emphasize cruciferous vegetables such as broccoli and cauliflower, dark leafy greens and bitter greens, for example.

There are also customizable “GI specific dietary interventions” for people with gastrointestinal complaints who have followed the elimination diet but are still experiencing symptoms. They include an antifungal (anti-Candida) diet, a low-FODMAP diet and others. The Mito Food Plan (“Mito” is short for mitochondria, the “energy factories” inside each cell) is designed to nutritionally support people with pain and fatigue syndromes as well as those who are at risk for autoimmune conditions or those experiencing neurological concerns. It is a strict anti-inflammatory, low-glycemic, gluten-free, low-grain, high-quality-fats approach to eating. There’s also a ReNew Food Plan, which can be used as a modified elimination diet and is designed to be “a whole systems reboot and system detox.” It’s geared toward people with autoimmune, gastrointestinal, neurological and other chronic health conditions. It eliminates sugar, dairy, grains (including gluten-free), alcohol, caffeine, artificial sweeteners, processed foods that contain heavy metals and foods high in pro-inflammatory saturated animal fats.

Do these customized versions really work? To be clear, they have not been studied in clinical trials but rather are based on clinical practice in functional medicine and related nutrition research. Various research projects are in the works—the Cleveland Clinic, for example, collaborated in the creation of the ReNew plan and is using it with some of its patients. The Cleveland Clinic is also using the Mito plan for certain patients of the clinic’s Center for Functional Medicine.

While the Core Food Plan is fine for anyone who’s generally healthy, the more personalized and specific versions are really designed to be undertaken with the supervision of a medical professional, nutrition professional or functional medicine health coach trained to customize the food plan to the individual. To find a health-care professional who is trained in the IFM approach, go to and choose “find a practitioner.” Additionally, the Functional Medicine Coaching Academy trains health coaches in collaboration with the IFM, and you may be able to find a nutrition coach through it.