What is healthy eating? Every day, new studies are showing what was actually supposed to be healthy is unhealthy and what we discard as unhealthy food might be healthy.

It’s confusing, watching science evolve. New research shows that reduced salt consumption might not reduce hypertension risk and can in fact be harmful to the body. Likewise, a different study shows that dietary cholesterol does not have any major impact on blood cholesterol. Both studies are the opposite of previous studies and widely held beliefs.

One major debate that has been going on is the need to avoid or consume saturated fat. While some studies say fats are unhealthy, new research challenges our existing findings and shows that they might not affect health negatively.

The 1960’s Diet-Heart Hypothesis

The recommendation for reducing the intake of saturated fat started with the theory that it causes heart disease. The ‘diet-heart hypothesis’ was first proposed by the University of Minnesota’s biologist Ancel Keys in the 1950s. Since then, North Americans have been advised to reduce their intake of fat, especially saturated fat, meat (including bacon)  and dairy products and tropical oils like palm and coconut are some of the main sources of saturated fats). In 1961, for the first time, a low-cholesterol, low-fat diet was recommended by the American Heart Association, which was based largely on the recommendations of Ancel Keys.

Canadians were asked to reduce fat intake in the 1970s by Nutrition Canada. And even now, the official Health Canada policy still warns against saturated fat. Their website states that saturated fats are not good for health and can increase the risks of heart disease as they affect cholesterol levels.

So then why, despite North Americans studiously avoiding fat intake, were markers of health falling?

The Other Side; Fats Are Healthy

Nina Teicholz, an investigative journalist, wrote a book about the myth of fat consumption leading to poor heart health. The book was written after nine years of research on fat and its relation with heart disease. During the research process, she interviewed many scientists and nutritionists who have been involved with this issue for many years. She proposed that instead of sound science, the diet-heart hypothesis was likely driven by commercial interests and the need of the American Heart Association to reaffirm the almost 70-year-old ‘heart healthy advice’.

The author claims that many of the studies that supported the diet-heart hypothesis were flawed, and that researchers working in favor of this hypothesis either delayed or ignored publishing the unsupportive data.

Teicholz said that bad science, industry bias, some strong personalities, and some scientific bullying led people to the wrong conclusion. She claimed that the reason behind heart disease is more likely polyunsaturated oil (like corn or soybean oil) and sugar consumption rather than the consumption of saturated fats.

Like Teicholz, some other scientists and experts also debunk the benefits of the low-fat diet. Some of them are Gary Taubes, an American science writer, South African science activist and author Tim Noakes, a Tasmanian orthopedic surgeon Dr. Gary Fettke, a Canada-based low-carb High Fat Diet advocate Dr. Jason Fung and others.

Of these, Fettke and Noakes and Fettke encountered legal battles in their country for promoting high-fat diets.

The PURE Study: No Link Between Fat Consumption and Heart Disease?

The Prospective Urban and Rural Epidemiological (PURE) Study, led by McMaster University’s Dr. Salim Yusuf, aimed to address lifestyle questions based on the underlying reasons for heart disease. The PURE study is a multi-year research based in 17 countries and involving 140,000 people. The preliminary findings of this study show that there is likely a connection between low consumption of fat to an increased heart disease risk. This hints that saturated fat could actually be beneficial. The team conducting the study also discovered that the reason behind heart problems may not be fat, but increased carbohydrate consumption. The study says that some fat is good, and some neutral, but carbohydrates are the main problem.

What Should You Eat? The Low Fat Quandary

The years-old beliefs and advice that doctors and nutritionists have been giving are being challenged by today’s scientists and researchers. It’s helpful to remember that science changes over time; as more research is carried out, modern technology assesses detailed inputs, then old information should be challenged.

Eating in moderation is vital. No food should be off limits (unless you’re allergic). Nutrient dense food should be prioritized, and that includes things like red meat, pork, beef, chicken, and lamb. Pork fat is very nutritionally dense—yes, that means bacon, pork belly, and pork chops can be back on the menu. Just remember to go for a walk afterwards; fitness is still vital for health, that hasn’t changed.