In the 1990s, people trying to lose weight were told to avoid foods that were high in fat, even if it meant eating foods high in sugar instead. Every few years, we see different advice on whether eggs are a healthy miracle food or a surefire way to set yourself up for an early heart attack.
Nutritional recommendations from scientists and experts seem to change frequently. But if these recommendations are rooted in science, and science is meant to be an objective view on the world, why do all these changes occur?
The Value of Eating Healthy
From the time we’re children, it’s important to eat as healthily as possible, prioritizing your nutritional needs while avoiding ingredients or eating patterns that could harm you. With better nutritional intake, your body has more complete access to all the individual components it needs to build muscle, maintain your health, and stave off illness.
Unfortunately, “eating healthy” is going to look different depending on what year you’re living in.
The Old Food Pyramid (and Other Misguided Suggestions)
People above a certain age have at least one clear example of misguided nutritional suggestions coming from the top: the USDA’s “food pyramid.” For many years, this pyramid advised people to eat 6 to 11 servings of carbohydrates like bread and pasta every day; we know now that excessive carbohydrate intake can lead to an excessive consumption of calories, while simultaneously increasing the risk of diabetes.
This is a particularly egregious example because it’s not just slightly off; it provided recommendations that arguably did harm to people. How did this happen? And why does it keep happening?
Why Nutritional Recommendations Change So Frequently
These are just some of the reasons why nutritional recommendations change so frequently:
1. The Irreducible Complexity of Nutrition
It’s incredibly difficult to understand nutrition on the level of individual components. Nutrition is a very complex field, with millions of different interactions that can’t be individually separated. As a simple example, it’s hard to understand the effects of sugar on the body when we very rarely consume sugar by itself. On top of that, every individual is unique in terms of genetics, environment, gut flora, and behavioral patterns – and all these variables can influence how nutrition affects you. In some ways, it’s impossible for scientists to make broad recommendations about nutrition, simply because every case is so complex and so unique.
2. The Demands of Long-Term Studies
If we really want to understand how nutrition affects our bodies and minds, we need to study those effects in the long term. Unfortunately, it’s very difficult and expensive to coordinate decades-long studies, so we don’t have many to review or learn from.
3. Flawed Data and Studies
Nutritional recommendations also suffer from flawed data and bad studies. If your sample size is too low, if you don’t have a proper control group, or if your study is influenced by profit-seeking corporations or governmental authorities, you’re going to end up with weak conclusions.
4. Misleading, Sensational Headlines
When most people talk about new developments in the world of nutrition, they’re not talking about the consensus of the scientific community. Instead, they’re probably talking about a series of headlines they saw across major news organizations. Unfortunately, these headlines are often misleading, since they’re often designed to be as sensationalized and polarizing as possible. Journalists are less interested in accurately reporting the facts and more interested in getting you to click on an interesting article, so we often see nutritional recommendations misstated or misrepresented in the news.
5. Third Party Influences
Another factor to keep in mind is the fact that not all people making nutritional recommendations have your best interests in mind. One simple example of this is the sugar industry paying scientists to attribute a rise in obesity to fat consumption, rather than sugar consumption. You must always keep the motivations of individuals in mind when considering whether to accept their stated conclusions – even if those individuals call themselves objective scientists.
What You Can Do
There isn’t much you can do to change the scientific community or our approach to journalism, but there are some corrective measures you can take now that you know why nutritional recommendations change so much:
1. Read Beyond Headlines
Never take a headline at face value. In some cases, they’re misleading. In other cases, they’re downright false. If you’re interested in the headline, read the article, and push yourself to read the original scientific research to fully understand what’s going on.
2. Consult Multiple Sources
Don’t assume that a single source has all the answers. Look at the work done by multiple different scientists to validate your hypotheses. If many different people are saying the same thing, it’s probably more likely to be true.
3. Take Recommendations with a Grain of Salt
Whenever an authoritative person or organization makes a recommendation about nutrition, take that recommendation with a grain of salt. There’s always a chance it could be labeled as untrue in a few years.
Nutrition is a very complex science, and we’re only starting to truly understand it. Today’s surefire recommendations may come under sharp scrutiny tomorrow, and we might as well throw out any information more than 20 years old. Still, healthy eating is important, so it’s important for us to continue advancing in this field so we can clear up our misconceptions and find more accurate nutritional guidelines.
