Four Nutrition "Rules" I Ignore

There's no shortage of lifestyle advice on the internet. It’s OK to take these so-called rules with a grain of salt.

I’ve been a registered dietitian for more than three decades and I’ve seen plenty of nutrition fads come and go. The internet repeats misinformation in a way that can make it seem like you must abide by certain rules for good health. Not so fast.

Avoid Seed Oils

Seed oils get a lot of hate, but it’s unfair. Seed oils are not “poisoning” us, and they aren’t to blame for America’s health problems, which is why I don’t shy away from them.

Seed oils are cooking oils derived from the seeds of plants. They’re used in home cooking and added to some processed foods. Seed oils include sunflower, canola, cottonseed, corn, soybean, safflower, grapeseed, and rice bran oils – what’s often referred to as the “Hateful Eight” on social media.

Seed oils contain omega-6 fats, a type of polyunsaturated fat. Polyunsaturated fats help to reduce low density liporotein (LDL) cholesterol, which is associated with a lower risk for heart disease and stroke.

Linolenic acid (LA) is the most common form of omega-6 fat found in seed oils. Linolenic acid helps maintain skin and cell health and is also a source of calories. The body can’t make LA so you must get it from food to survive.

Critics of seed oils point to the fact that the body converts LA to the fatty acid arachidonic acid (AA). Arachidonic acid can be used to make compounds that promote inflammation, blood clotting, and higher blood pressure, which is probably why seed oils get so little respect.

Yet, suggesting that people limit seed oils to curb LA intake in order to reduce AA levels is an oversimplification of how the body works. The body can also convert AA into compounds that reduce inflammation and blood clots.

There’s no scientific evidence to back up the notion that seed oils should be banished from the diet. On the contrary.

An October 2024 review of the evidence about seed oils published in the British Journal of Nutrition found that observational studies often show a higher intake of LA lowers inflammation as well as the risk for cardiovascular disease (CVD) and type 2 diabetes. Another review published in 2023 found that omega-6 fatty acid intake protected against cardiovascular disease.

The American Heart Association supports the inclusion of omega-6 fatty acids including LA as part of a healthy diet. In addition, the World Cancer Research Fund has found no proof that seed oils in moderation increase cancer risk.

Seed oils can be a beneficial part of a balanced diet. The trick to using any added oil, including olive or avocado oil, is to balance it with other nutrients to stay within your daily calorie allowance (everyone has one!). Each tablespoon of added oil has about 125 calories.

Don’t Eat Processed Foods

There’s a lot of buzz about processed foods, particularly the ultraprocessed kind. Here’s why I don’t avoid either type.

Most of the food you eat is processed: it’s been cooked, crushed, canned, milled, pasteurized, frozen, or dried, has additives such as salt, vitamins, minerals, fiber, sweeteners, or food coloring, or has been altered in other ways that qualifies it as processed. Everyday foods including olive oil, canned tuna fish, and salted peanuts are processed foods.

NOVA is the most widely-used system to classify foods by processing. Though soft drinks, including the sugary and artificially-sweetened kind, orange cheese puffs, and candy are low-nutrient, ultraprocessed food (UPF), there are many foods NOVA calls UPF that I recommend eating on a daily basis.

The NOVA system has been criticized for its lack of objectivity and for the fact that it doesn’t consider the nutrient content of foods. The system puts foods such as flavored tofu, seltzer water, peanut butter, and packaged whole wheat bread into the UPF category, based solely on processing.

There’s no question that a high UPF intake can crowd out more nutritious foods and lack adequate protein, fiber, vitamins, and minerals. But there’s no reason to dismiss UPF out of hand.

Instead of thinking of foods as good or bad based on processing, consider their nutritional merits. A balanced eating pattern that’s rich in fiber, low in saturated fat, sodium, and added sugar is the best policy in midlife and beyond. Most of the time, choose foods that are nutrient-rich, affordable, and figure in with your cultural preferences and dietary needs. That’s what I do.

Don’t Eat Fruit Because It’s High in Sugar

Photo by Jonas Kakaroto on Unsplash

This is one of the craziest nutrition myths I’ve heard for several reasons. Most people know that excess sugar can harm their health, but it’s rare for people to eat too much sugar in the form of fruit. (The recommendations about sugar refer to added sugar, not the kind that occurs naturally in food.) According to the Centers for Disease Control and Prevention, people living in the U.S. consume only about half the recommended two to three servings of fruit daily, so there’s no reason to warn people off fruit.

Including fruit can result in a lower calorie intake, according to a 2016 research review published in Nutrients. The study concluded that fruit is a relatively low-calorie food that’s filling, and that people who eat fruit may have an easier time of weight control.

Fruit also contains fluid, fiber, vitamins, minerals, and phytonutrients, which are powerful plant compounds that protect your cells from damage that can result in health problems. As a nutrient powerhouse, fruit helps reduce the risk for inflammation that can lead to chronic illness while supporting gut health and the immune system.

People with diabetes don’t need to avoid fruit as long as it’s part of a balanced diet. A study with about 187,000 adults published in the British Medical Journal in 2013 found that eating more of certain fruits, particularly blueberries, grapes, and apples, was associated with a lower risk of developing type 2 diabetes.

If you’re concerned about sugar, read Nutrient Facts panels on food packages to discover the amounts of added sugar in foods. The Dietary Guidelines for Americans recommends limiting added sugar intake to fewer than 10% of daily calories, which amounts to about 50 grams or less on a 2,000-calorie eating plan.

Get 10,000 Steps Every Day

It’s not a nutrition rule, but I had to mention it anyway.

There’s nothing wrong with trying to include 10,000-steps every day, but you should know this fitness mantra began as an arbitrary goal from a 1960s marketing campaign to sell pedometers. If you feel bad about not taking 10,000 steps daily, consider that the research says you can benefit by taking fewer steps.

Moving around more and sitting less during the day is beneficial in many ways. A 2023 European Journal of Preventive Cardiology meta-analysis demonstrated that at least 2,337 daily steps reduced the risk of dying from cardiovascular disease. In a 2020 JAMA study of 4,840 men and women, researchers found that 8,000 steps a day offered twice the protection against dying from any cause compared to taking 4,000 daily steps, which also offered benefits. And a 2022 JAMA Neurology study found a link between 9,800 steps daily with a reduced risk for dementia, though fewer steps provided protection for the brain and in other ways.

Getting older is usually synonymous with weight gain and related health issues, such as type 2 diabetes and heart disease. People who don’t do any other form of exercise will likely benefit from aiming for a higher daily step count, but I don’t aim for 10,000 steps daily because I’m a runner and I work out five to six days a week. However, I try to take as many steps as possible during the day by doing chores like shopping for groceries and bringing the bags in the house one at a time, yard work, taking the stairs whenever possible, and walking the dog every day.

What do you think? Are there nutrition rules you don’t follow? Let me know!