“A calorie is a calorie” is an oft-repeated dietary slogan, and not overeating is indeed an important health measure. Rather than focusing on calories alone, however, emerging research shows that quality is also key in determining what we should eat and what we should avoid in order to achieve and maintain a healthy weight. Rather than choosing foods based only on caloric value, think instead about choosing high-quality, healthy foods, and minimizing low-quality foods.
There isn’t one “perfect” diet for everyone, owing to individual differences in genes and lifestyle.
One study analyzed whether certain foods were more or less likely to promote weight gain. This type of research examining specific foods and drinks allows us to understand whether “a calorie is a calorie,” or if eating more higher-quality foods and fewer lower-quality foods can lead to weight loss and maintenance.
Researchers in the Department of Nutrition at Harvard School of Public Health show us that quality is in fact very important in determining what we should eat to achieve and maintain a healthy weight, and that the notion of “a calorie is a calorie” does not tell the whole story.
View the HSPH news release, “Changes in specific dietary factors may have big impact on long-term weight gain: Weight-loss Strategy to Only ‘Eat Less, Exercise More” May be Overly Simplistic’”
With the proliferation of macronutrient-based diets over the past several decades, from low-fat to low-carbohydrate, discussion of the three main macronutrients – carbohydrates, proteins, and fats – has become standard when talking about optimal diets. Researchers have begun comparing these “macronutrient management”-style diets to one another in order to determine which is most effective, but thus far evidence is largely inconclusive.
One study, published in JAMA in 2007, compared four weight-loss diets ranging from low to high carbohydrate intake. This 12-month trial followed over 300 overweight and obese premenopausal women, randomly assigning them to either an Atkins (very low carbohydrate), Zone (low carbohydrate), LEARN (high carbohydrate), or Ornish (very high in carbohydrate) diet.
Another study, published in The New England Journal of Medicine in 2009, challenged the above study’s findings by testing four different types of diets and producing results that showed comparable average weight loss among the different diets.
An additional study, published in The New England Journal of Medicine in 2010, looked at the role of protein and glycemic index upon weight loss maintenance. Researchers first implemented a low-calorie diet to produce weight loss, then examined whether protein and glycemic index impacted weight loss maintenance.
The results from these three studies suggest that there may be some benefits to a macronutrient-based dietary approach, but research also shows that while a particular diet may result in weight loss for one person, it may not be effective for another person due to individual differences in genes and lifestyle. For those seeking the “perfect” one-size-fits-all diet, then, there isn’t one! The great news is that everyone can follow The Healthy Eating Plate guidelines and choose healthy, flavorful foods to create a diet that works best for you.
23. Mozaffarian, D., et al., Changes in diet and lifestyle and long-term weight gain in women and men. N Engl J Med, 2011. 364(25): p. 2392-404.
24. Gardner, C.D., et al., Comparison of the Atkins, Zone, Ornish, and LEARN diets for change in weight and related risk factors among overweight premenopausal women: the A TO Z Weight Loss Study: a randomized trial. JAMA, 2007. 297(9): p. 969-77.
25. Sacks, F.M., et al., Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates. N Engl J Med, 2009. 360(9): p. 859-73.
26. Larsen, T.M., et al., Diets with high or low protein content and glycemic index for weight-loss maintenance. N Engl J Med, 2010. 363(22): p. 2102-13.
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Use healthy oils (like olive and canola oil) for cooking, on salad, and at the table. Limit butter. Avoid trans fat.
Drink water, tea, or coffee (with little or no sugar). Limit milk/dairy (1-2 servings/day) and juice (1 small glass/day). Avoid sugary drinks.
The more veggies — and the greater the variety — the better. Potatoes and French fries don’t count.
Eat plenty of fruits of all colors
Choose fish, poultry, beans, and nuts; limit red meat and cheese; avoid bacon, cold cuts, and other processed meats.
Eat a variety of whole grains (like whole-wheat bread, whole-grain pasta, and brown rice). Limit refined grains (like white rice and white bread).
Incorporate physical activity into your daily routine.
Create healthy, balanced meals using this visual guide as a blueprint.
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