I took a pledge the other day that will surprise my longtime followers. It even surprised me. I pledged to drop the term “low-fat” from my vocabulary. I was not alone, but in a room full of nutrition scientists, dietitians, doctors, chefs and food service titans. We were all at the Culinary Institute of America in the Napa Valley for a retreat called “Worlds of Healthy Flavors,” an educational initiative designed to help corporate and executive chefs of chain restaurants, volume food-service operations (such as campus dining) and supermarkets expand their options for healthy meal choices. The CIA teamed up with Harvard School of Public Health in 2004 to launch the initiative, and every year nutrition scientists present their findings to this select group.
Taking the ‘no more low-fat’ pledge
We were asked to take the low-fat pledge by Dr. Ronald Krauss, a senior scientist and the director of atherosclerosis research at Children’s Hospital Oakland Research Institute. Krauss was echoed by another eminent cardiologist and epidemiologist, Dr. Dariush Mozaffarian, who co-directs the program in cardiovascular epidemiology at Brigham and Women’s Hospital and Harvard Medical School and is an assistant professor at the Harvard School of Public Health. Both of these doctors have been involved in numerous studies measuring the effects of dietary habits on cardiovascular health and disease. They and many of their colleagues have found little evidence that low-fat diets are any better for health than moderate or high-fat diets.
“No randomized trial looking at weight change has shown that people did better on a low-fat diet,” Mozaffarian told us, and there have been dozens of them. “For many people, low-fat diets are even worse than moderate or high-fat diets because they’re often high in carbohydrates from rapidly digested foods such as white flour, white rice, potatoes, refined snacks and sugary drinks.” They are also often dangerously high in sodium, as salt is often added to processed foods (along with sugar and starch) to compensate for the lack of flavor from fats.
“The only time I use the term ‘low-fat’ is when I’m telling people not to use the term ‘low-fat,’ ” Krauss proclaimed. “The term should be banned from our vocabulary, along with ‘fatty.’ ” In stigmatizing the concept of fat, we are giving many healthy foods a bad reputation, foods like avocados, nuts, plant oils (olive, canola, soybean, walnut and other nut oils) and many types of fish.
Hands shot up in the audience. Many of the dietitians and communicators made the point that reducing fats was an easy way to reduce calories, and this was significant in light of the obesity epidemic.
What does fat have to do with obesity?
“The calorie issue and the obesity epidemic are confusing the issues,” Dr. Krauss responded. What studies have been finding time and again is that many people who eliminate fats from their diets overcompensate with less healthy alternatives. Healthy fats increase satiety and this has an impact on weight control.
A major problem for the general public, and for people who inform the public, is that there is a big gap between science and policy, and consequently science and public perception. For the most part, the scientific community agrees that total fat doesn’t affect heart disease, though saturated fat does. But the messages we’ve been getting since the early ’90s haven’t caught up with the latest research. That’s why values for total grams of fat are mandated on food packaging labels. Mozaffarian says that these values should be dropped from food labels. “It is not a helpful concept.” It would be more helpful if the values listed were for unsaturated fat and saturated fat, he says.
What type of fat is it?
Although the percentage of calories from fat has not been shown to have an effect on disease outcomes, the type of fat is extremely important. That’s why the removal of trans-fats from food service is such a success story. Trans-fats are unhealthy, period, significantly raising the risk of heart disease if eaten on a regular basis. Saturated fat — the kind found in animals and dairy products, as well as in any hydrogenated fat — is also regarded as a less healthy fat because it raises LDL cholesterol, or “bad” cholesterol in the blood, and this kind of cholesterol is related to heart disease. But even saturated fat is not so bad compared to refined carbohydrates, the doctors say, and if we were to eliminate it from our diet we would also be eliminating many foods that are also rich in healthy fats, like fish, whose omega-3 fatty acids are vital to good health.
The fats that have measurable health benefits are polyunsaturated fats, the type found in plants, nuts, and seafood. Scientists place seafood omega-3s, plant omega-3s (found in walnuts, canola oil, flax seeds, leafy greens), and plant omega-6s (found in corn oil, soybean oil, and safflower oil) at the top of their benefits list, followed by the monounsaturated fats found in olive oil and peanut oil.
Surprise: Olive oil doesn’t rank highest when it comes to fat
This I found a bit confusing. I thought olive oil was the king of healthy oils. It is, but not because it’s a monounsaturated fat. It turns out that the quality of the fat in olive oil is somewhat neutral – it does no harm but has not been shown to have the kind of benefits found in omega-3s and -6s. Those health benefits that Mediterranean populations have long reaped from olive oil may be coming not from the fats but from trace nutrients, the plant polyphenols that are also present in the oil.
So what are all of those heart patients who owe their improved health to the Ornish diet to think? Clearly this diet has worked for many. But did it work because the patients stopped eating saturated fats and started eating more grains and vegetables, or because they stopped eating all fats?
And what about my own work? There are many recipes in my cookbooks from the ’90s that now look and taste dated to me. I’ve put back some of the oil and cheese that I took out when editors were telling me to keep total fat at 30 percent of total calories – a concept that is now obsolete even among policymakers. But I’ll continue to cook on the light side because that’s the way I prefer to eat. Mine is a love for vegetables rather than a disdain for fat, and if those vegetables taste just as good cooked in 2 tablespoons of olive oil as they do when cooked in a quarter cup, I’ll go with the lower amount. But I also won’t hesitate to increase that amount if I find that a little bit of extra oil, drizzled over the top of my kale or winter squash gratin, makes all the difference in the world.
Photo: butter. Credit: istockphoto.com, Craig Veltri