Losing weight is a challenge, but choosing a diet that fits your lifestyle and gets results can be difficult, too. Many popular diets may help with fast weight loss in the short term, but each has risks, and some are more effective than others in the long term.
Nutrition experts recommend diets that you can maintain over time and that also provide health benefits. This is true for both men and women, as there is little if any evidence that certain diets are more effective for men vs. women – even if some popular diets are marketed more to one or the other. It’s more about personal preferences and individual factors.
The definition of a good weight loss plan changes according to who is setting the goals, what nutrition guidelines are involved, and how the plan balances exercise and diet. Also, the definition of a healthy diet changes as new research shows how different foods, essential nutrients, and other food components affect health. Making a decision about diets can feel overwhelming, with so much information coming from so many sources and when weight loss remains a leading health topic in traditional media, social media, and online searches.
Health care experts say the most effective diets focus on nutrition details that vary depending on your needs. But they also make a general recommendation: Choose a diet that you can follow long-term.
Staying the Course
Barbara Roberts, a registered dietitian with UAB Diabetes and Nutrition Education Services, says the most effective diets are ones that are sustainable.
“A sustainable diet is a nutrition plan you can stick to,” Roberts says. “Diets with strict limitations, or those that call for permanent lifestyle changes, aren’t possible for most people. A modified diet allows you to include some foods that are not ideal along with those that are the more healthy choices, and that’s often a better diet because it’s easier to stay with the plan. Otherwise, you may go on and off with a strict diet and never get results.”
Roberts points to a common frustration for people trying popular or “fad” diets. They may lose some weight right away and temporarily improve their health, but they likely will struggle to maintain that diet for longer than a year or two. Then the weight returns, and the process starts again.
Roberts says people usually can avoid that cycle by avoiding diets that are mainly presented through infomercials, magazine ads, or celebrity recommendations. With diet advertisements in fitness and lifestyle magazines, much of the information provided is not backed up by research, recent surveys show.
“One indicator of a fad diet is that the information supporting it comes almost entirely from testimonials,” Roberts says. “That’s not evidence-based medicine. The information you use to find a diet plan should come from research. But making an appointment to see a nutritionist is not as instantly engaging as reading an article in a magazine or listening to Dr. Oz.”
Keto and Paleo Diets
Two of the most popular but restrictive diets are the keto diet and the paleo diet. Each plan may provide quick weight loss and specific short-term benefits. However, in recent surveys, health care experts and wellness professionals list both diets at the bottom among choices for a sustainable diet plan.
The ketogenic or “keto” diet is designed to make the body use a different type of fuel. Instead of relying on sugar (glucose) that comes from carbohydrates such as grains, legumes (nuts/seeds/beans), vegetables, and fruits, the keto diet uses ketone bodies, which the liver produces from stored fat. The long-term health effects and the safety of this diet remain unknown due to limited research.
The keto diet is associated with an increase in saturated fat (linked to liver illness) and LDL cholesterol (linked to heart disease). There’s also a risk for shortages in micronutrients such as magnesium, phosphorus, and vitamins B and C. Low-carb diets may even affect certain brain functions by limiting the amount of glucose available.
The Paleolithic or “paleo” diet is a weight loss plan based on consuming only the types of food eaten during the Paleolithic era (also known as the Stone Age), when humans hunted animals and gathered food from nature. Humans at that time did not grow crops or raise animals. Most paleolithic diets included only meats, fruits, nuts, and vegetables but almost no cereals, grains, or milk products.
Today, the paleo diet plan eliminates dairy products, grains (such as cereals, corn, breads, and pasta), sugar, potatoes, beans, soybeans, and lentils. This high-protein diet may create health risks due to foods high in saturated fat and overall fat. Some studies suggest that this diet offers health benefits. But nutrition experts say there aren’t enough studies with large enough sample sizes to prove health claims about the paleo diet.
A large and growing body of evidence from research studies indicates that some diet plans reduce the risk of non-communicable diseases (NCDs), such as heart disease and cancer. The Mediterranean diet and the DASH diet are in this category. The good news is that these plans also are effective for maintaining weight loss.
The Mediterranean diet focuses on whole grains, fruits and vegetables, legumes, olive oil, and some lean meat and fish. Studies show that this diet offers more success than low-carb diets for weight loss (after one year) and for heart health. Choosing a more plant-based diet was found to help the majority of people lose weight, possibly because of the increased fiber. Other studies show a decrease in inflammation and a reduction in body mass index (BMI), a measure used to broadly categorize people as underweight, normal weight, overweight, or obese based on tissue mass.
The Dietary Approaches to Stop Hypertension (DASH) diet is designed to lower blood pressure by focusing on vegetables, fruits, and low-fat dairy, along with whole grains, lean meats, and nuts. The plan follows sodium guidelines for reducing hypertension (high blood pressure).
Research indicates that eating a plant-based diet is associated with a lower risk for type 2 diabetes and heart disease, and people who closely follow plant-based diets have up to a 25% lower risk of dying from NCDs.
“Even if you are more concerned with weight loss than with other reasons when you first start a diet plan, the best in terms of sustainable success are the DASH diet or Mediterranean diet,” Roberts says. “Obviously we recommend them for the health benefits, but an eating plan that is easy to follow and meets most people’s needs is a recipe for success in the long term. And the long term is what counts.”