Lately I’ve read and heard some different things about fat (as in the nutrient in food, not body fat) and I realized I’ve never addressed my views about food fat content on this blog. Fat has been a controversial nutrient in American public health dialogue for almost fifty years now, since scientists realized that consumption of dietary fat, especially animal fat, was associated with the mounting incidence of coronary heart disease. So the government started encouraging the public to eat a lower fat, higher carbohydrate diet, focusing on fat as the villain. In response, the food industry started manufacturing low-fat products, sometimes reducing the oil in a snack food, or sometimes re-engineering typically high fat products like cheese to have a lower fat content.
There is a contingent of health professionals and other stakeholders who look back on this low-fat fad as the instigator of our collective sugar and carb addiction. They say the focus on lowering fat consumption encouraged overconsumption of carbohydrates and consequent weight gain, which led to the obsession with low-carb, high protein and fat diets, now popular in the Paleo incarnation. They say that reducing fat clearly did nothing for public health.
This claim, however, is dependent upon the assumption that people actually reduced their fat consumption in the first place. In fact, the research tells us that the average fat percentage of the average diet has actually stayed constant throughout both the low fat and low carb fads. And even if fat were the villain it was made out to be, replacing higher fat foods with nutrient-devoid, sugar and salt-filled processed foods that are easy to overeat wouldn’t be likely to fix the problem anyway.
So what is really the deal with fat? Should we avoid it, should we slather it on? Here’s my pretty educated opinion.
It is pretty clear that excess amounts of saturated fat, the type found mostly in animal products, raises blood cholesterol and promotes inflammation and chronic disease. So in general I try to avoid that type of fat. This is one of the myriad reasons I avoid animal products in general. The same is true of trans fats, which come almost exclusively from man-made partially hydrogenated oils, and are most likely worse for our health than saturated fats. Fortunately, trans fats have been disappearing from the food supply for years now and are now in the process of being phased out completely.
As for other sorts of fats, you definitely need to have some quantity of unsaturated fatty acids in your diet for optimal functioning, and possibly a bit more to help prevent chronic disease. Omega-3 fatty acids, which come in high quantities in fish, although you can also get them from plant sources, seem to be particularly important in fetal development and may discourage inflammation. Fish, nuts, nut butters, avocado, and cooking with oils are all healthy sources of these essential fatty acids. Not only are these important nutrients by themselves, but they also are critical for absorption of fat-soluble vitamins A, D, E, and K.
But here’s the caveat. Any high fat food like nuts or avocado is going to be very calorie dense, which can be problematic if you’re trying to watch your weight. Olive oil may be good for you, but cook with a lot of it or drown your salad in it and it’s a recipe for weight gain. Deep frying can be done in healthy oils too, but it makes for a much higher calorie meal, not to mention lower in nutrients and potentially higher in carcinogens.
So I advocate a low-fat diet for two reasons. One is that lower in total fat usually means lower in animal products, which means lower in harmful saturated fat. Two is that lower in total fat, particularly added fat like cooking oils and salad dressings, means less chance of excess calories. And I don’t mean go into the store and pick the products labeled “low-fat.” If you are eating a large variety of whole, plant-based foods, your diet will be naturally low in fat because most plant-based foods are. Go ahead and spread some peanut butter on your toast and roast your veggies with a little oil, just don’t go overboard.
The real tragedy here is that public health interventions are still way too focused on individual nutrients and not enough on making sure people have enough access to whole, nutritious foods. Thanks for reading!