Five Eating Plans That are Supported with Research

There are limitless possibilities when it comes to deciding what to eat. Hundreds of diets exist, with some being fad diets and others being well-established and backed by research. With such a surplus of information out there, it is difficult to discern what diets are truly healthy and nutritious. This article will discuss five common eating plans and the evidence supporting their use.

1. Low carbohydrate

Low carbohydrate diets, also termed “low-carb” diets, are one of the many eating tactics used to improve overall health. Although this plan’s general strategy is to restrict carbohydrate intake, there is no clear definition of what constitutes a low-carb diet. In research, studies typically measure “low-carb” by either total daily carbohydrate intake or ratio of daily macronutrient intake. In the context of carbohydrate intake, experts categorize diets in the following four ways:

• Very low carbohydrate: A diet consisting of less than 10 percent carbohydrates or 20 to 50 grams per day
• Low carbohydrate: A diet consisting of less than 26 percent carbohydrates or less than 130 grams per day
• Moderate carbohydrate: A diet consisting of 26 to 44 percent carbohydrates
• High carbohydrate: A diet consisting of 45 percent or more carbohydrates

Low and very low carb diets are most known for their ability to induce weight loss. Restricting carbohydrate intake lowers insulin, a natural hormone involved in fat storage processes in the body. Lowering insulin improves cardiometabolic processes, thus causing a reduction in weight. Additionally, if you lessen your carbohydrate intake, you may replace carbs with other macronutrients such as proteins and fats. Proteins and fats prevent hypoglycemia and increase satiety, which is the feeling of fullness after meals. Through these mechanisms, you naturally feel less hungry, decrease how much you eat, and eat in a calorie deficit.

In addition to weight loss, low carb diets can improve other related conditions, including type II diabetes and cardiovascular disease risk. Therefore, limiting carbohydrates is a mainstay of glycemic control in diabetes. Carbohydrates increase insulin requirements; thus, minimizing dietary carbohydrates can better blood sugar control. One study demonstrated this benefit when a ketogenic diet decreased insulin, hemoglobin A1c, and the need for oral diabetes medications in participants. Other evidence exists suggesting that low carb diets can decrease triglycerides and increase high-density lipoprotein (HDL), also known as “good” cholesterol.

Implementing a low carbohydrate diet involves several steps. In the first two to four weeks of this diet, you should focus on minimizing carbohydrate intake to 20 to 50 grams daily. In doing so, it is important to first ignificantly reduce intake of added sugar and refined carbs. In the maintenance phase of a low carb diet, you may increase total carbohydrate intake depending on your health goals¹.

2. Mediterranean

A Mediterranean diet is one of the healthiest ways to eat and is a great way to maintain long-term health results. There is no official definition of a Mediterranean diet, but this eating plan focuses on food patterns originating from the Mediterranean region. It involves eating whole foods, plants, and healthy fats. The cornerstone of a Mediterranean diet includes:

• Eating an abundance of vegetables, fruit, beans, nuts, and lentils
• Having whole grains such as brown rice and whole wheat bread
• Intaking healthy fats, such as extra virgin olive oil
• Consuming meats such as fish or poultry and avoiding red meats
• Limiting sugar and butter

Because there is no strict definition of a Mediterranean diet, the foods you eat can be tailored to your specific needs, preferences, and medical history. When transitioning to a Mediterranean diet, you can also start by making simple switches in your everyday diet. For example, switch white rice with brown rice or use olive oil instead of butter.

Eating a Mediterranean diet can have profound effects on several aspects of your health. One of the biggest benefits is heart disease prevention. One large study showed that eating a Mediterranean diet could decrease one’s risk of heart disease by up to 30 percent. Another study indicated that Mediterranean-like eating delayed plaque buildup in artery walls, thus decreasing the risk of premature death by 80 percent.

A Mediterranean diet induces these positive effects for several reasons. These include:

• Minimizing saturated and trans fat, which are traditionally known as “unhealthy” fats. Eating unhealthy fats increases cholesterol, induces inflammation, and raises your risk for atherosclerosis. Mediterranean-like eating promotes intake of unsaturated fats, which are healthier fats, like omega-3 fatty acid.
• Decreasing refined carbohydrate intake. Like a low-carb diet, a Mediterranean diet stresses the importance of minimizing the amount of refined carbs and sugar you eat. These cause more drastic spikes in blood sugar and have little if any nutritional benefit.
• Decreases sodium intake. Having too much sodium can increase your blood pressure, elevating your risk of a stroke or heart attack.
• Lowering inflammation. Refined foods and obesity can cause chronic inflammation, which can cause conditions such as diabetes and heart disease. Additionally, Mediterranean diets are higher in antioxidants and fiber, which can help decrease inflammation throughout the body^2,3.

3. Paleo

Paleo originates from the term “Paleolithic”. Thus, a paleo diet focuses on eating foods similar to our ancient ancestors. These ancestors' diets were restricted to what they could gather, hunt, or fish. Likewise, vegetables, meat, and fish are the cornerstone to a paleo diet. Other types of foods, like carbohydrates and dairy, are eaten in moderation in this type of diet. The idea is that complex carbohydrates are important to a well-rounded diet, however, refined carbs and sugar should be minimized.

A paleo diet can be a healthy eating strategy if done correctly. A nutritious paleo diet consists of foods high in fiber, antioxidants, and potassium but minimizes sodium, simple carbohydrates, and sugar. Paleo diets also focus on eating natural foods, such as those that are organic, local, and non-GMO⁴.

One study analyzed 2,000 individuals following either a paleo or Mediterranean diet. Both groups demonstrated similar results, however, those eating a paleo diet reduced oxidative stress, all-cause death, and death from cancer. In another study evaluating overweight women, a paleo diet improved insulin sensitivity and decreased triglyceride levels⁵. Likewise, a paleo diet may be beneficial eating strategy for individuals looking to better their health.

4. Vegan

A vegan diet eliminates any foods that originate from animals, such as meat, dairy, or eggs. Instead, it focuses on plant-based foods such as fruits and vegetables. The American Dietetic Association (ADA) concludes that well-planned vegan diets can be appropriate diets. However, there is some concern that vegans may become deficient in certain nutrients such as protein, vitamin D, calcium, vitamin B12, iron, essential fatty acids, iodine, and zinc.

Some postulate that veganism is healthier than a traditional diet. One meta-analysis bolstered this hypothesis, concluding that vegetarians had a 9 percent lower mortality rate than omnivores. Although the study did not analyze vegans specifically, there of course is some overlap between the two diets. Evidence also exists that those eating large amounts of fruits and vegetables tend to live longer. Another long-term study supports this fact, concluding that after 13 years of follow-up, individuals that had the highest intake of fruits and vegetables had a 34 percent lower risk of all- cause death. As plants are the cornerstone of a vegan diet, one may extrapolate these benefits to veganism. However, ensuring appropriate supplementation and intake of all nutrients is important^6,7.

5. Gluten Free

In recent years, the gluten-free diet has emerged as a popular eating plan for many, even those that do not have celiac disease. A gluten-free diet eliminates foods containing gluten, a protein found in grains such as wheat. In a gluten-free diet, you do not eat foods like pasta, bread, or cereal.

A gluten-free diet is essential for those with celiac disease, a condition characterized by an autoimmune response to gluten. Individuals may also have gluten sensitivity, where gluten can cause symptoms like diarrhea, constipation, bloating, or stomach pain. In these instances, a gluten-free diet can be beneficial.

Others have tried a gluten-free diet to lose weight. If cutting out gluten, you may naturally eliminate refined carbohydrates and processed foods that typically contain gluten. Likewise, you may notice a reduction in your weight as a result. However, eliminating gluten may also lower your intake of other important nutrients such as fiber, iron, B vitamins, and magnesium. It is also important to understand that many gluten-free foods are highly processed, meaning they contain additional ingredients high in fat, sodium, and sugar. These can cause other health implications such as increased blood pressure and even weight gain.

There are some potential risks associated with going gluten-free. Therefore, unless you have celiac disease or are gluten sensitive, it is best to start by eliminating processed foods prior to gluten.

Conclusion

Low carbohydrate, Mediterranean, paleo, vegan, and gluten-free diets are all different ways of eating that have gained traction over the years as eating strategies. One of these diets may be right for you depending on your medical history, health goals, and personal preferences. As with any lifestyle change 

Author

David J. Bauder, PA-C David Bauder, PA-C, is a certified physician assistant and the assistant medical director at Weight Loss and Vitality in Manassas and Alexandria, Virginia, Washington, DC; and Gaithersburg, MD. He enjoys helping patients optimize their physical and mental health to improve their overall well-being. He earned his physician assistant degree from the University of Texas Health Science Center at San Antonio. Afterward, he gained admission into the reputable graduate program for physician assistant studies at the University of Nebraska Health Science Center in Omaha. David has over 26 years of experience working as a physician assistant. He’s practiced in podiatry, family medicine, emergency medicine, general surgery, urgent care, and functional medicine.