Eric Rimm

Eric Rimm

The best diet? One you can follow

August 13, 2012 — No ‘Magic Bullet’ When It Comes to Choosing a Diet

High-fat, low-fat, low-carb, gluten-free…. One look at the dizzying array of diet books on bookstore shelves pitching the latest diet craze is enough to make you question which diets are simply passing fads, and which ones really work.

In the fourth of the Harvard School of Public Health’s summer Hot Topics lecture series, Eric Rimm provided advice for those wanting to lose some pounds in his talk, “Deconstructing Popular Weight Loss Diets.” The lecture was held July 31, 2012 in FXB G-13.

“Is there a magic bullet to losing weight? Probably not,” said Rimm, associate professor in the departments of epidemiology and nutrition at HSPH and director of the Program in Cardiovascular Epidemiology.

Rimm gave an overview of what’s known scientifically about some of the more popular diets. Regarding the low-fat diet craze of recent years, he said, “A low-fat diet is not a viable weight loss option for most people.” Recent studies tracking progress on a range of weight loss plans found low-fat diets generally don’t work and can sometimes be harmful because people need some healthy fats in their diets.

Research shows many popular diets result in a modest weight loss, reduced cholesterol, and improved insulin sensitivity with moderate compliance over several months, said Rimm. But when these participants are followed over the course of a year, compliance tends to slip and much of the weight is regained. In some studies, women in control groups who didn’t adjust their diets ended up at the same approximate weight as the dieters after one year.

Ease of adherence to a meal plan—how easily people can stick to it over time— is one of the most important attributes to any diet. The macronutrient composition may not matter as much, especially since many diets include similar healthy options—fruits, vegetables, whole grains, nuts, and the like, only in different proportions, said Rimm.

“There’s no perfect diet. Adherence to the diet one selects rules the day,” he said.

Here are some tips from Rimm on successful weight loss:

  • Tailor your diet: Successful diets tailored to individuals’ personal and cultural preferences are more likely to result in long term success.
  • Get support: Ongoing counseling sessions are important to achieving and maintaining weight loss.
  • Eat a range of food choices, including fruits, vegetables, whole grains, and nuts.
  • Unprocessed foods are best. Stay away from processed food.
  • Fats: Not all fats are created equal. Replace unhealthy fats, such as trans fats and partially hydrogenated vegetable oils, with healthy fats, such as olive oil or canola oil (mono and polyunsaturated fats). Use liquid cooking oils and check nutrition labels on products you buy for fat content.
  • Fish: If you are able, try to eat two servings of fish weekly or consider fish oil supplements to get an average 250mg/day of omega 3s or n-3 fatty acids. Choose your fish wisely to avoid mercury, especially if you are pregnant, thinking of becoming pregnant, or a small child or infant. Albacore tuna, shark, and swordfish are among the fish with higher mercury levels.
  • Alcohol: A number of studies have shown moderate alcohol consumption to have some health benefits, such as to heart health and increased longevity. However, deciding whether to drink alcohol or not is a personal decision and not advisable if you are at risk for alcoholism. Studies also have shown that one drink a day can increase women’s breast cancer risk by 10%. If you do drink, do so sensibly and in moderation: up to one drink per day for women and up to two drinks per day for men.
  • Consider following HSPH’s Healthy Plate as a guide to healthy eating.
  • Dark chocolate can be good for blood pressure—just don’t consume too much of it.

Learn more

HSPH’s The Nutrition Source

Many Paths to Successful Weight Loss (The Nutrition Source)

The Best Diet is the One You’ll Follow (The Nutrition Source)

Ask the Expert: Healthy Fats (The Nutrition Source)

–Marge Dwyer

photo: Aubrey LaMedica