The message that we should switch from consuming saturated to unsaturated fats has resonated loudly for decades. But last year, the U.S. Centers for Disease Control and Prevention reported that in spite of that recommendation, national obesity rates among adults have continued to rise — from 33.7 percent in 2007–08 to 39.6 percent in 2015–16 — as the number of people with type 2 diabetes reaches epidemic proportions. A UCLA Health nutrition expert says that it’s not necessarily that people are ignoring the recommendation to reduce animal fats; the problem, says Zhaoping Li, MD, PhD, director of the UCLA Center for Human Nutrition, is that many are replacing those fats with the wrong foods.
With so much emphasis on the importance of reducing our intake of saturated fats, why do obesity and type 2 diabetes continue to rise among U.S. adults?
Since around the 1980s, people have been getting the message that they need to cut back on saturated fats, such as those in meat and dairy foods. But the tendency has been to switch liberally to carbohydrates, without thought to the overall calories coming in. Too many people mistakenly think of fat as bad and anything other than fat as good. But it is important to remember that fat, particularly in a protein like meat, may have satisfied your hunger more than carbs. So if you cut back on fat, you’re less likely to feel full and you may end up eating more.
Is there a natural tendency to crave carbohydrates when cutting back on saturated fat?
Yes. When we reduce saturated fats, it’s natural to be driven toward carbs. The three pillars for taste are fat, sugar and salt. If you cut out fat, you’re going to gravitate toward the carb side. But to our bodies, carbohydrates are interchangeable with saturated fats. When we eat carbs, the liver immediately converts them to triglycerides, which is the most prevalent saturated fat in animal foods like meat. At any given time, an average person carries about five grams of sugar in the blood. That’s a cube of sugar. A can of soda, as an example, is nine cubes. When the body can’t use the sugar, it immediately converts it to triglycerides. So drinking that soda is more efficient than eating a piece of lard in terms of its becoming saturated fat in the body.
What’s the best strategy for reducing fats without ending up consuming more carbs and calories?
When you compare fat, protein and carbs, it is protein that is the most satiating. Therefore, it’s always good to replace fat with healthy proteins. Chicken and turkey breast, egg whites and seafood are examples of foods that are high in protein and low in fat. And the best source of carbohydrates is vegetables, and, to some degree, fruit. Vegetables provide key micronutrients, which are important because we now know that every bite we take is to feed not only our human cells but also our gut bacteria as well. Each of us carries about 100 trillion-to-300 trillion gut bacteria, referred to as the gut microbiome. That atmosphere changes based on what we eat, and it plays a major role in our overall health. If we’re just eating refined carbs, nothing gets to those bacteria. We’re also beginning to learn that the gut microbiome plays a role in satiety, and even in mood.
There is good fat and there is bad fat. What is the hierarchy?
The best fats are the long-chain omega-3s — fish such as salmon and albacore tuna — and monounsaturated fatty acids, like those found in such foods as avocados, olive oil and tree nuts. Then you have polyunsaturated — corn, soybean and safflower oils. And then saturated, which is found in beef, pork, butter and cheese. The worst are trans fats — the artificially altered adulterated fats like partially or completely hydrogenated fats — found in fried foods, vegetable shortening, premade baked goods and coffee creamers.
Finding a balance is the key, right?
Yes. If you want to have a piece of steak, which has quite a bit of saturated fat, make sure to eat healthy the rest of the day, with minimal fat and less carbohydrates. What matters in the new dietary guidelines is the big picture, focusing on overall calories and dietary patterns. The specifics are going to differ with each person, depending on genetics and lifestyle. If you tell me, as a Chinese woman, to avoid fat, I have no problem, because I didn’t grow up with it; carbs are my concern. And as a working woman, it’s unrealistic to recommend that I prepare three meals a day. There will never be one recommendation that fits everyone. People should talk with their physician or a registered dietitian to determine what will be best for them.