If you follow nutrition news you have no doubt noticed that recommendations change over time. Foods you thought were good for you can suddenly show up on a “never eat” list and foods you had learned to avoid are now recommended. This makes it challenging to follow a healthy diet, for sure. It may also make you question the advice of nutrition experts, who seem to change their minds periodically.
This is the topic of my Health & Fitness column in the Aiken Standard this week.
There are several reasons for this. First, carefully designed long-term studies of food and health are difficult to conduct. This means that small differences can appear to be more important than they really are and meaningful effects may not be statistically significant. Additionally, it is unreasonable to carefully control what people eat over years or decades, so “proving” that a food is either beneficial or harmful to health is almost impossible. This leads to health claims that probably shouldn’t be made as well as missed opportunities to make useful recommendations.
There are also political reasons why nutrition advice can change over time. The long-held belief that eating fat causes obesity and heart disease was largely based on decisions made by politicians. Importantly, these decisions were not based on good research. This led to a recommendation to eat more carbohydrates instead, something the food industry embraced.
Low-fat foods that were high in sugar became known as health food, despite evidence to the contrary. Even as evidence linking sugar intake with poor health accumulated, Congress forbid U.S. dietary guidelines to include an “eat less” recommendation. Only now are we changing our thoughts and behaviors to consume less added sugar and be less fearful of fats in our diet.
Here are two examples of nutrition advice that was well-meaning at the time but hasn’t worked out in the long run. In fact, these recommendations may actually have made us less healthy.
Low-Fat and Fat-Free Foods
The recommendation to eat less fat resulted in foods that normally would contain fat to be reformulated to have less, or no, fat. The fat was replaced by sugar and other additives leading to ingredient lists that read more like a chemistry experiment than food. We know now that these highly processed foods were no healthier and are thought to be a major cause of the obesity epidemic.
Sugar Free foods
Now that we have embraced the idea that we should eat less added sugar, there are sugar-free alternatives to most foods and beverages. The problem is that foods containing sugar are meant to taste sweet, so something must be added to replace the sugar. More often than not, the sugar is replaced by artificial sweeteners that contain no calories but still add sweetness.
There are two problems with this. First, although these foods tend to be calorie-free, they are still associated with weight gain. Second, they may be sweeter than the food they replace and alter our expectation of what food should taste like. This is especially true for children, who learn to expect that all food should be sweet. Furthermore, the alternative sweeteners used to replace sugar may not be as safe as we initially thought.
The bottom line is that all nutrients—carbohydrates, fat, and protein—are healthy within relatively broad ranges. And getting these nutrients, fats and sugar included, from real food is always preferable to eating processed foods. The key to good health is to balance what you eat with daily physical activity at work, at the gym, or at home. And remember that nutrition researchers and experts are doing their best to bring you reliable recommendations, even if it doesn’t come across that way in the news!