Fat-free foods are healthier than high-fat foods. Potatoes are bad for you. Plant milk is better for you than cow’s milk.
Some false ideas about nutrition seem to hang on.

So, to set the record straight, we asked top nutrition experts in the United States a simple question: What is one nutrition myth you wish would go away — and why? Here’s what they said.

Myth No. 1: Fresh fruits and vegetables are always healthier than canned, frozen or dried varieties. Research has found that frozen, canned and dried fruits and vegetables can be just as nutritious as their fresh counterparts. One caveat: Some canned, frozen and dried varieties contain sneaky ingredients such as added sugars, saturated fats and sodium, said Sara Bleich, a professor of public health policy at the Harvard T.H. Chan School of Public Health, so opt for products that keep those ingredients to a minimum.

Myth No. 2: All fat is bad.

The vilification of fats led many people — and food manufacturers — to replace calories from fat with calories from refined carbohydrates such as white flour and added sugar.

But healthy fats found in olive and other plant oils, avocados, fish and certain nuts can actually help reduce your risk for conditions such as heart disease and stroke.

Myth No. 3: ‘Calories in, calories out’ is the most important factor for long-term weight gain. It’s true that if you consume more calories than you burn, you will probably gain weight. And if you burn more calories than you consume, you will probably lose weight — at least for the short term. But “it’s the types of foods we eat that may be the long-term drivers” of obesity , said Dr. Dariush Mozaffarian of Tufts University.

Ultraprocessed foods — such as refined starchy snacks, cereals, crackers, energy bars, baked goods, sodas and sweets — can be particularly harmful for weight gain .

Myth No. 4: People with Type 2 diabetes shouldn’t eat fruit.

This myth stems from conflating fruit juices — which can raise blood sugar levels because of their high sugar and low fiber content — with whole fruits.

Myth No. 5: Plant milk is healthier than dairy milk.

There’s a perception that plantbased milks, such as those made from oats, almonds, rice and hemp, are more nutritious than cow’s milk. “It’s just not true,” said Kathleen Merrigan, a professor of sustainable food systems at Arizona State University . Consider protein: Typically, cow’s milk has about 8 grams of protein per cup, whereas almond milk typically has around 1 or 2 grams per cup, and oat milk usually has around 2 or 3 grams per cup.

Many plant-based beverages have more added ingredients — such as sodium and added sugars — than cow’s milk.

Myth No. 6: White potatoes are bad for you. Potatoes have often been vilified in the nutrition community because of their high glycemic index — which means they contain rapidly digestible carbohydrates that can spike your blood sugar. However, potatoes a re rich in vitamin C, potassium, fiber and other nutrients, especially when consumed with the skin. They are also inexpensive and found year-round in grocery stores .

Myth No. 7: Fundamental nutrition advice keeps changing — a lot. This is not the case, said Dr. Marion Nestle, a professor emerita of nutrition, food studies and public health at New York University.

“In the 1950s, the first dietary recommendations for prevention of obesity, Type 2 diabetes, heart disease and the like advised balancing calories and minimizing foods high in saturated fat, salt and sugar. The current U.S. Dietary Guidelines urge the same.” Yes, science evolves, but the bottomline dietary guidance remains consistent. As author Michael Pollan distilled to seven simple words: “Eat food. Not too much. Mostly plants.”