Is a Super Low-Fat Diet Best for Heart Health?
A new, much-publicized report in the Journal of the American Dietetics Association crowns Dean Ornish's super-low-fat diet as the winner in the best-for-your-heart competition. Let's nibble at the edges.
Bottom line first
Here's how the 8 diets studied scored (out of 70 possible points)
- Ornish: 64.6
- WeightWatchers high-carbohydrate: 57.4
- New Glucose Revolution: 57.2
- South Beach Phase 2: 50.7
- Zone: 49.8
- MyPyramid: 48.7
- Weight Watchers high-protein: 47.3
- Atkins 100-g carbohydrate: 46
- South Beach Phase 3: 45.6
- Atkins 45-g carbohydrate: 42.3
This study in 50 words or less
Researchers chose 8 popular diets: Weight Watchers, the USDA's Food Pyramid diet, and diets based on five books ranked highest on the New York Times best-sellers list. They then chose a one-week eating plan from each and analyzed them in light of the Alternate Healthy Eating Index, which assesses dietary factors linked to good heart health.
Yes, but. . .
There are more caveats here than there are fruits and veggies in a Dean Ornish salad. Some of the most significant limitations:
- Nobody followed these diets to test them. This was a component analysis of menus, not of outcomes or compliance.
- The diets were studied for their potential benefit for heart health, not for weight loss. Ideally people choose an eating plan for its health benefits. More often they choose based on its presumed ability to deliver weight loss.
- Results weren't consistent across diet brands--the phase or type of diet tested affected results considerably.
So what are you going to do about it?
The fact that this study took on the question of heart health is itself useful. If you're concerned with heart disease, it's wiser to choose an eating plan for its heart benefits than for weight loss.
The diets were scored according to the following factors, which researchers have linked to improved heart health: nine servings of fruits and vegetables per day, and one each of nuts and soy protein; a 4-to-1 ratio of white meat to red meat; 15 grams per day of grain fiber; very little or no trans fat; and at least as much polyunsaturated fat as saturated fat. These factors are worth taking into account on any heart-healthy eating plan.
Compliance is a key factor with any heart-health eating plan: Both Ornish's super-low-fat and Atkins low-carb diets are notoriously difficult to follow in the long run. In studies, Weight Watchers programs have shown better results in long-term compliance. A heart-healthy eating plan should be something you can stick with for good.
Worth noting: Somewhat surprisingly, the federal government's food-pyramid diet ranked in the middle.
Check in with our new heart-health expert dietician, Melanie Thomassian, who will take your questions or comments.
Consult our resources on heart-healthy eating.