Which Diet Is Right for You?

Obesity is running rampant throughout the world. Here's how you can cut through the noise about the latest fads and make meaningful, lasting changes.

The world is in an obesity epidemic, especially in the US. In fact, Centers for Disease Control and Prevention (CDC) research shows about 42 percent of Americans are now obese. What’s more, being significantly overweight or obese is a far bigger cause for concern than just worrying about how your clothes fit. Excess pounds raise your risk of health problems — including type 2 diabetes, heart disease, stroke, and some types of cancer.

Naturally, there’s been an ongoing wave of new diets and advice about how to shed unwanted pounds over the past couple of years.

You can find plenty of diet plans online telling you what and how much you should eat and what to avoid. You’ll no doubt find some questionable claims that specific supplements or herbs, often sold by the websites in question, will help “melt” or otherwise quickly reduce your excess fat.

Many time-tested commercial plans have been around for years because they do result in weight loss for many people. Examples include Weight Watchers, Atkins, South Beach, Zone, and Jenny Craig. Most involve sales of books, meal plans, and packaged meals that eliminate the guesses when it comes to calorie counting.

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How do you sort out which diet is best for you?

The truth is, if you’re eating fewer calories — and stick with it — all diets work.

“We know from research that any diet will help you lose weight. It’s just a matter of cutting calories,” said Joan Salge Blake, EdD, RD, LDN, program director and clinical professor of nutrition at Boston University. She explains that dieting is not very complicated: it’s simply a matter of numbers. Eat less and take in fewer calories, or combine eating less with moving more, “which is the best combination,” Blake emphasized.

“But the question is, is it a) healthy for the long term and b) can you really sustain it in the lifestyle that you have? And often times the answer is no, no because the weight comes back on,” Blake said. “We have a lot of Americans out there who are experts at losing weight. The issue is keeping the weight off.”

Ideas about weight-loss diets have changed

In addition to being overwhelmed by the sheer volume of information, many people are confused about which type of diet to follow. For years we were bombarded with the mantra: Eat a well-balanced, low-fat diet. Then we heard the enemy wasn’t fat — instead, it was carbohydrates.

The diet tide eventually turned again, with recommendations that dieters should avoid all saturated fats. But in recent years, researchers studying weight loss concluded it’s only the “wrong” type of fat that’s harmful to health and contributes to weight gain.

The saturated fat warnings were applied to diet recommendations because saturated fat can raise your level of the "bad" cholesterol, LDL, increasing your heart disese risk, according to Alice H. Lichtenstein, D.Sc, senior scientist and director of the Cardiovascular Nutrition Laboratory and professor of nutrition science and policy at Tufts University.

As she explained in an interview with the NIH News in Health newsletter, however, research showed a problem when dieters jumped on the “low-fat” and “no-fat” band wagons.

Many of those diets added fat-free versions of crackers, cookies, ice cream, and other snacks made with refined grains and sometimes sugar. Yet, replacing saturated fat with carbs helped with neither weight loss nor heart disease risk, Lichtenstein reported.

“There’s still this misconception that eating fat — any kind of fat — is bad. That it will lead to heart attacks, or weight gain. That’s not true. People really should be encouraged to eat healthy fats,” added Frank Sacks, MD, a nutrition expert and professor of cardiovascular disease prevention at Harvard University.

In fact, Sacks advises including healthy fats in your diet, such as canola, peanut, safflower, soybean, and olive oil, along with nuts, seeds, avocadoes, and fatty fish (like salmon and sardines). These “good” fats not only help curb appetites and keep weight under control but also can lower heart risks.

In moderation, especially, it turns out some saturated fat may not be a problem. In fact, recent studies suggest that some full-fat dairy products, such as yogurt, may have heart benefits, according to Ronald Krauss, MD, who researches cholesterol at the UCSF Benioff Children’s Hospital Oakland.

What about going on a “cleanse” of only vegetable and fruit juices for a few days to jump start weight loss? That approach is one to avoid, diet expert Blake warned.

“The body doesn’t need a cleaning diet. It can clean itself,” she said. “Your body needs protein to maintain health and muscle mass, and if you go many, many days without protein, your body is going to start breaking down your lean muscle mass to provide the protein that it needs for other functions in the body,” Blake said.

That, in turn, can slow your metabolism, which is not going to promote weight loss over time.

Which diet is right for you?

While simply cutting back on calories and increasing your physical activity will lead to some weight loss, it takes finding a diet you can stick with long-term to keep extra pounds off.

When you’re evaluating which diet to try, consider what is required and whether you can make it part of your permanent lifestyle rather than just a short-term fix.

“The best diet to go on is going to be something that is going to be able to get the weight off and that is enjoyable, tastes good, and allows you to keep eating like this for a very long time,” Blake said.

Keep your weight-loss goals realistic

One of the reasons people fail at diets is they have unrealistic expectations to begin with about how much and how fast they can lose weight.

“Don’t assume that there’s a quick way to get off something that’s been happening for a while. A change in lifestyle got you into this weight predicament and that means a change in lifestyle is going to get you out of this predicament,” Blake said.

You should aim to lose about 10 percent of your body weight over a 6-month period, according to Blake. This approach individualizes weight-loss based on your starting weight.

Here are four popular diet choices that have research to back their effectiveness:

Go low carb, but not to the extreme.

When low-carb diets were first super popular, some people ate almost no carbs at all and, while they enjoyed quick weight loss, it wasn’t the healthiest, most sustainable approach. Researchers at the Harvard T.H. Chan School of Public Health cite numerous studies showing a moderately low-carbohydrate diet is best. It can not only reduce weight but also help heart health, as long as protein and fat selections come from healthy sources.

Keto is low carb, too, but high in fats.

Ketogenic diets are extremely low carb and high fat, with over 70 percent of calories in meals from fats. This causes your body to go into a ketogenic state, breaking down fat into molecules, called ketones, which become the primary energy for many cells in your body. The result is rapid weight loss and, often, lower glucose levels.

The diet can also cause side effects, including fatigue and dizziness, which usually pass as you continue the diet.

Although keto diets are fairly new for weight loss in the general public, they have been used in medicine for decades to treat certain forms of epilepsy. Keto diets are also being studied as a possible treatment for some types of cancer, according to the National Cancer Institute.

Going keto may help treat type 2 diabetes, too, but it can also cause blood glucose to drop too low, making it extra important to talk to your doctor before trying this diet if you have diabetes.

Intermittent fasting means not eating for a certain time.

There are three versions of this diet. Some people fast for one day, then eat regularly the next. Others eat normally five days a week and fast for two. But the most popular, and probably easiest, approach to fasting is known as restricted eating, which means restricting eating to 8 to 10 hours a day and fasting the other 14 to 16 hours.

Studies have shown fasting can help:

• Lower your weight
• Treat symptoms of metabolic syndrome (including high blood pressure, elevated blood glucose, and high levels of “bad” cholesterol)
• Reduce the “spare tire” around your waist
• Help treat obesity

While fasting, you can have water, tea, and coffee. When it’s time to eat, stick to whole grains, fruits, vegetables, lean protein, and healthy, plant-based fats.

The DASH diet can lower weight and blood pressure.

The DASH (Dietary Approaches to Stop Hypertension) diet was created decades ago by researchers at the National Institutes of Health (NIH) to improve heart health. The eating plan was designed to lower the risk of high blood pressure by emphasizing less sodium and more foods rich in heart-healthy potassium.

Numerous studies have shown the DASH approach to eating is beneficial to the cardiovascular system. There’s also a bonus. You can use it for weight loss, if you have the self-discipline to stick to eating the healthy foods that are included in the DASH diet. These include fresh fruit, vegetables, nuts, whole grains, and low-fat dairy products.

The DASH diet minimizes sugary foods and drinks, fatty meats, and unhealthy oils (like palm oil). The NIH offers a free DASH Eating Plan online.

The bottom line

It’s important to opt for a weight-loss diet that works and is healthy. It's important to talk to your doctor about which diet is best for you, especially if you have a significant amount of weight to lose or you have any chronic health condition. If you have difficulty planning meals to fit into your diet plan, ask for a referral to a registered dietitian for help.

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