2.4.2. Popular Diets

Popular Diets

The concept of functional foods represents initiatives aimed at addressing health problems. Certain diet plans take this concept one step further, by striving to prevent or treat specific conditions. For example, it is widely understood that people with diabetes need to follow a particular diet. Although some of these diet plans may be nutritionally sound, use caution because some diets may be fads or be so extreme that they actually cause health problems.

Before experimenting with a diet, discuss your plans with your doctor or a registered dietitian. Some of the more popular diets fall under the category of fad diets, while others are backed by scientific evidence. Those that fall into the latter category provide a good foundation to build a solid regimen for optimal health including weight management.

The DASH Diet

The Dietary Approaches to Stop Hypertension, or DASH diet, focuses on reducing sodium intake to either 2,300 milligrams per day (as recommended by the Dietary Guidelines for Americans and Health Canada) or 1,500 milligrams per day for certain populations. The DASH diet is an evidence-based eating plan that can help reduce high blood pressure. This plan may also decrease the risk of heart attack, stroke, diabetes, osteoporosis, and certain cancers.[1]

DASH tips to lower sodium include the following:

  • using spices instead of salt to add flavor
  • reading sodium content on processed or canned food labels, and choosing low-sodium options
  • removing some sodium from canned foods (such as beans) by rinsing the product before consumption
  • avoiding salt when cooking

DASH dieters are recommended to consume a variety of whole grains and high-fiber fruits and vegetables, and moderate amounts of low-fat dairy products, lean meats, and heart-healthy fish.

In addition, DASH limits the use of saturated fats to less than 7 percent of total calories, and limits the consumption of sweets and alcohol.

The DASH diet also calls for consuming less added sugar and drinking fewer sugar-sweetened drinks.

DASH replaces red meat with fish and legumes and calls for increased calcium, magnesium, potassium, and fiber. Also, even though some people on the DASH diet may find it lowers their HDL (good) cholesterol along with their LDL (bad) cholesterol, it still has a positive cumulative effect on heart health.[2]

The Gluten-Free Diet

The gluten-free diet helps people whose bodies cannot tolerate gluten, a protein found in wheat, barley, and rye. One of the most important ways to treat this condition is to avoid the problematic foods, which is not easy. Although following a gluten-free diet is challenging, it is prescribed for patients with gluten intolerance and celiac disease, an autoimmune disorder with a genetic link. People who have celiac disease cannot consume gluten products without damaging their intestinal lining. Eating a gluten-free diet means finding replacements for bread, cereal, pasta, and more. It also means emphasizing fresh fruits, vegetables, and other foods without gluten.

However, it is important to note that the gluten-free trend has become something of a fad even for those without a gluten intolerance. Celiac disease is a relatively rare condition found in only 1 percent of the population. Therefore, a gluten-free diet should be followed only with a physician’s recommendation.

Low-Carb Diets

Low-carb diets, which include the Atkins Diet and the South Beach Diet, focus on limiting carbohydrates—such as grains, fruit, and starchy vegetables—to promote weight loss. The theory behind the low-carb diet is based on the fact that insulin prevents the breakdown of fat by allowing sugar in the form of blood glucose to be used for energy. Proponents of this approach believe that because limiting carbs generally lowers insulin levels, it would then cause the body to burn stored fat instead. They believe this method not only brings about weight loss, but also reduces the risk factors for a number of conditions. However, some studies have shown that people who followed certain low-carb diet plans for two years lost an average of nearly 9 pounds, which is similar to the amount of weight lost on higher carbohydrate diets.[3]

The benefits of this kind of diet include an emphasis on whole, unprocessed foods and a de-emphasis of refined carbohydrates, such as white flour, white bread, and white sugar. However, there are a number of downsides. Typically, the first two weeks allow for only 20 grams of carbs per day, which can be dangerously low. In addition, dieters using the low-carb approach tend to consume twice as many saturated fats as people on a diet high in healthy carbohydrates. Low-carb diets are also associated with a higher energy intake, and the notion that “calories don’t count,” which is prevalent in this kind of diet, is not supported by scientific evidence.[4]

The Macrobiotic Diet

The macrobiotic diet is part of a health and wellness regimen based in Eastern philosophy. It combines certain tenets of Zen Buddhism with a vegetarian diet and supports a balance of the oppositional forces of yin and yang. Foods are paired based on their so-called yin or yang characteristics. Yin foods are thought to be sweet, cold, and passive, while yang foods are considered to be salty, hot, and aggressive.

Whole grains make up about 50 percent of the calories consumed and are believed to have the best balance of yin and yang. Raw and cooked vegetables comprise about 30 percent of the diet and include kale, cabbage, collards, bok choy, and broccoli on a daily basis, along with mushrooms and celery a few times a week. Bean or vegetable-based soups and broths can make up 5 to 10 percent of daily caloric intake. Additionally, the diet allows small amounts of fish and seafood several times a week, along with a few servings of nuts. The macrobiotic diet prohibits certain foods, such as chocolate, tropical fruits, and animal products, because they are believed to fall on the far end of the yin-yang spectrum, which would make it difficult to achieve a Zen-like balance.

The macrobiotic diet focuses on foods that are low in saturated fats and high in fiber, which can help to lower the risk of cardiovascular disease. Proponents of this diet also believe that it may protect against cancer. However, many nutritionists and healthcare providers express concerns, particularly if the diet is followed strictly. Extreme macrobiotic eating can be low in protein, low in calories, and pose a risk for starvation. In addition, the diet is also very low in essential vitamins and minerals.[5]

The Mediterranean Diet

The traditional Mediterranean diet incorporates many elements of the dietary choices of people living in Greece and southern Italy. The Mediterranean diet focuses on small portions of nutritionally-sound food. This diet features food from plant sources, including vegetables, fruits, whole grains, beans, nuts, seeds, breads and potatoes, and olive oil. It also limits the consumption of processed foods and recommends eating locally grown foods rich in micronutrients and antioxidants. Other aspects of this eating plan include consuming fish and poultry at least twice per week, eating red meat only a few times per month, having up to seven eggs per week, and drinking red wine in moderation. Unlike most diets, the Mediterranean diet does not cut fat consumption across the board. Instead, it incorporates low-fat cheese and dairy products, and it substitutes olive oil, canola oil, and other healthy oils for butter and margarine.

More than fifty years of nutritional and epidemiological research has shown that people who follow the Mediterranean diet have some of the lowest rates of chronic disease and the highest rates of longevity among the populations of the world. Studies have shown that the Mediterranean diet also helps to decrease excess body weight, blood pressure, blood fats, and blood sugar and insulin levels significantly.[6]

Tools for Change

For six years, researchers from the University of Bordeaux in France followed the dietary habits of more than seven thousand individuals age sixty-five and over. Participants who described greater consumption of extra-virgin olive oil reportedly lowered their risk of suffering a stroke by 41 percent. The study controlled for stroke risk factors, such as smoking, alcohol intake, high blood pressure, and a sedentary lifestyle. To increase the amount of olive oil in your diet, try spreading olive oil instead of butter on your toast, making your own salad dressing using olive oil, vinegar or lemon juice, and herbs, cooking with olive oil exclusively, or simply adding a dose of it to your favorite meal.[7]

The Raw Food Diet

The raw food diet is followed by those who avoid cooking as much as possible in order to take advantage of the full nutrient content of foods. The principle behind raw foodism is that plant foods in their natural state are the most wholesome for the body. The raw food diet is not a weight-loss plan, it is a lifestyle choice. People who practice raw foodism eat only uncooked and unprocessed foods, emphasizing whole fruits and vegetables. Staples of the raw food diet include whole grains, beans, dried fruits, seeds and nuts, seaweed, sprouts, and unprocessed produce. As a result, food preparation mostly involves peeling, chopping, blending, straining, and dehydrating fruits and vegetables.

The positive aspects of this eating method include consuming foods that are high in fiber and nutrients, and low in calories and saturated fat. However, the raw food diet offers little in the way of protein, dairy, or fats, which can cause deficiencies of the vitamins A, D, E, and K. In addition, not all foods are healthier uncooked, such as spinach and tomatoes. Also, cooking eliminates potentially harmful microorganisms that can cause foodborne illnesses. Therefore, people who primarily eat raw foods should thoroughly clean all fruit and vegetables before eating them. Poultry and other meats should always be cooked before eating.[8]

Vegetarian and Vegan Diets

Vegetarian and vegan diets have been followed for thousands of years for different reasons, including as part of a spiritual practice, to show respect for living things, for health reasons, or because of environmental concerns. For many people, being a vegetarian is a logical outgrowth of “thinking green.” A meat-based food system requires more energy, land, and water resources than a plant-based food system. This may suggest that the plant-based diet is more sustainable than the average meat-based diet in the U.S. By avoiding animal flesh, vegetarians hope to look after their own health and that of the planet at the same time. Broadly speaking, vegetarians eat beans, grains, and fruits and vegetables, and do not eat red meat, poultry, seafood, or any other animal flesh. Some vegetarians, known as lacto vegetarians, will eat dairy products. Others, known as lacto-ovo vegetarians, will eat dairy products and eggs. A vegan diet is the most restrictive vegetarian diet—vegans do not eat dairy, eggs, or other animal products, and some do not eat honey.

Vegetarian diets have a number of benefits. Well-balanced eating plans can lower the risk of a number of chronic conditions, including heart disease, diabetes, and obesity. They also help to promote sustainable agriculture. However, if a vegetarian does not vary his or her food choices, the diet may be insufficient in calcium, iron, omega-3 fatty acids, zinc, and vitamin B12. Also, if people who follow these diets do not plan out their meals, they may gravitate toward foods high in fats.

See Table “The Pros and Cons of Seven Popular Diets” for a summary of this discussion.

Table The Pros and Cons of Seven Popular Diets

Diet Pros Cons
DASH diet
  • Recommended by the National Heart, Lung, and Blood Institute, the American Heart Association, and many physicians
  • Helps to lower blood pressure and cholesterol
  • Reduces risk of heart disease and stroke
  • Reduces risk of certain cancers
  • Reduces diabetes risk
  • There are very few negative factors associated with the DASH diet
  • Risk for hyponatremia
Gluten-free diet
  • Reduces the symptoms of gluten intolerance, such as chronic diarrhea, cramping, constipation, and bloating
  • Promotes healing of the small intestines for people with celiac disease, preventing malnutrition
  • May be beneficial for other autoimmune diseases, such as Parkinson’s disease, rheumatoid arthritis, and multiple sclerosis
  • Risk of folate, iron, thiamin, riboflavin, niacin, and vitamin B6 deficiencies
  • Special gluten-free products can be hard to find and expensive
  • Requires constant vigilance and careful food label reading, since gluten is found in many products
Low-carb diet
  • Restricts refined carbohydrates, such as white flour and white sugar
  • May temporarily improve blood sugar or blood cholesterol levels
  • Not entirely evidence-based
  • Results in higher fat and protein consumption
  • Does not meet the RDA for carbohydrates to provide glucose to the brain
Macrobiotic diet
  • Low in saturated fats and high in fiber
  • Emphasizes whole foods and de-emphasizes processed foods
  • Rich in phytoestrogens, which may reduce the risk of estrogen-related cancers
  • Not entirely evidence-based
  • Lacks certain vitamins and minerals; supplements are often required
  • Can result in a very low caloric intake
  • Lack of energy may result from inadequate protein
Mediterranean diet
  • A reduced risk of cardiovascular disease and mortality
  • A lower risk of cancer
  • De-emphasizes processed foods and emphasizes whole foods and healthy fats
  • Lower sodium intake, due to fewer processed foods
  • Emphasis on monosaturated fats leads to lower cholesterol
  • Highlighting fruits and vegetables raises consumption of antioxidants
  • Does not specify daily serving amounts
  • Potential for high fat and high calorie intake as nuts and oils are calorie-dense foods
  • Drinking one to two glasses of wine per day may not be healthy for those with certain conditions
Raw food diet
  • Emphasizes whole foods
  • Focuses on nutritionally-rich foods
  • Not entirely evidence-based
  • Very restrictive and limits protein and healthy fat intake
  • Could encourage the development of foodborne illness
  • Extremely difficult to follow
  • High in fiber which can cause essential nutrient deficiencies
Vegetarianism and veganism
  • May reduce some chronic diseases such as cancer, heart disease, and Type 2 diabetes
  • May help with weight reduction and weight maintenance
  • Guidelines regarding fat and nutrient consumption must be followed
  • Higher risk for nutrient deficiencies such as protein, iron, zinc, omega-3, vitamin B12
  • Consumption of a high fiber diet interferes with mineral and nutrient bioavailability
  • Vegetarian and vegan protein sources are lower quality with majority missing at least one essential amino acids

  1. DASH Diet Eating Plan. DASH Diet Oregon.  http://www.dashdietoregon.org/. Accessed April 12, 2018.
  2. DASH Diet Eating Plan. DASH Diet Oregon. http://www.dashdietoregon.org/. Accessed April 12, 2018.
  3. Low-Carb Diet: Can It Help You Lose Weight?.The Mayo Clinic.  http://www.mayoclinic.com/health/low-carb-diet/NU00279. Accessed March 6, 2018.
  4. Steele V. Health and Nutritional Effects of Popular Diets. Kellogg Nutrition Symposium, The Team of Registered Dietitians & Nutrition Professionals at Kellogg Canada Inc. Insert to Canadian Journal of Dietetic Practice and Research 64, no. 3.
  5. Zelman, KM. Macrobiotic Diet. http://www.webmd.com/diet/features/macrobiotic-diet. Updated February 9, 2018. Accessed April 12, 2018.
  6. Robinson, K. The Mediterranean Diet. http://www.webmd.com/diet/features/the-mediterranean-diet. Published February 6, 2018. Accessed April 15, 2018.
  7. More Olive Oil in Diet Could Cut Stroke Risk: Study. MedicineNet.com. https://www.medicinenet.com/script/main/art.asp?articlekey=145823. Published 2011. Accessed April 15,2018.
  8. Raw Food Diet. WebMD.com.https://www.webmd.com/diet/a-z/raw-foods-diet. Published November 21, 2016. Accessed April 15, 2018.


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Fundamentals of Health and Physical Activity by Kerri Z. Delaney and Leslie Barker is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.