We are bombarded with diet and nutrition advice. It comes from friends and family, social media, blogs, news, magazines, fitness instructors, healthcare professionals, and other sources.
If everyone acts like a nutritionist, it is inevitable that false, misleading and unscientific information will emerge and become permanent.
Here are five persistent nutrition myths and what you need to know about them:
1. Avoid fruits as they are loaded with sugar
It is said that eating fruit will prevent you from losing weight, or worse, will make you gain weight. Or if you are diabetic, you cannot eat fruit.
Fruit gets an unfair bad rap for its sugar content. This is especially true for bananas, although one medium banana contains only slightly more sugar than a similarly sized apple or pear.
Whole fruit contains naturally occurring sugar, as well as vitamins, minerals, phytochemicals, and fiber, which slow the absorption of sugar into the bloodstream.
A 2021 study found that higher fruit intake protects against type 2 diabetes (including bananas!) compared to eating little or no fruit. And if you have diabetes, research suggests that adding fruit to your diet may help improve blood sugar control.
It is true that some people may need to limit their fruit intake. However, not all fruits need to be avoided. I’m sure most of us could stand to eat more fruit.
2. Consume protein immediately after training
You may have been told that to optimize muscle growth, you should consume protein within 30 minutes of finishing strength training.
Doing this within this “anabolic window” is said to allow your muscles to repair and recover more effectively than if you wait longer for your post-workout nutrition.
But a review of 43 randomized controlled trials published in 2013 found that consuming protein within 60 minutes of training had little effect on muscle building. However, a strong predictor of muscle gain was the ability to consume total daily protein requirements.
Don’t have time to grab a protein shake right after your workout? Don’t stress.
But be sure to include enough protein in your daily diet to support your fitness goals. And spread this protein over three or four meals.
3. Soy increases the risk of breast cancer
This idea revolves around soy’s isoflavones, which are natural plant compounds that have a very weak estrogenic effect.
A woman’s risk of developing breast cancer is related to the estrogen produced by her ovaries.
Soy isoflavones are structurally different from human estrogen. Soy isoflavones do not affect the body’s natural estrogen after consumption.
No studies in humans have found that soy consumption increases the risk of breast cancer. In fact, some studies suggest that soy may protect against breast cancer and breast cancer recurrence.
As part of a healthy diet, moderate intake of soy foods (one to two servings per day) does not increase the risk of breast cancer. Traditional soy foods such as tofu, tempeh, edamame and soy milk are good sources of protein, fiber and other nutrients.
4. Dairy products are inflammatory
Ongoing low-grade inflammation is associated with a variety of chronic diseases, including heart disease, stroke, type 2 diabetes, cancer, inflammatory bowel disease and rheumatoid arthritis.
A diet high in refined carbohydrates, added sugars, red meat, and saturated fats and low in fruits, vegetables, whole grains, and omega-3 fats is considered inflammatory.
It is common to hear that dairy products (milk, yogurt, cheese) are inflammatory. Perhaps this is because dairy products contain saturated fat, which can increase inflammation.
But evidence does not support a link between dairy products and inflammation. Some studies have linked dairy products, especially fermented dairy products (yogurt, aged cheese, kefir), to a lower risk of type 2 diabetes and cardiovascular disease.
A 2021 review of 27 randomized controlled trials found that dairy products had a neutral or beneficial effect on blood markers of inflammation in adults without a serious inflammatory disorder. Studies show that fermented dairy products have weak anti-inflammatory effects.
Unless you have a milk allergy, there’s no reason why your anti-inflammatory diet shouldn’t include dairy products. Mediterranean, DASH and Scandinavian diets certainly do.
5. Eating nuts causes weight gain
Eating a handful of hazelnuts every day is thought to help protect against heart disease, type 2 diabetes and cancer. Hazelnuts are also an important component of diets that lower blood pressure and blood cholesterol.
However, many people avoid eating nuts for fear of gaining weight.
Nuts are high in calories due to heart-healthy unsaturated fats. But there is no evidence that eating nuts regularly leads to weight gain.
Instead, many studies have found that consuming nuts is associated with less weight gain and a lower risk of overweight and obesity.
The protein, fiber and fat in nuts increase satiety and reduce appetite. It has been shown that people who eat nuts consume fewer calories at subsequent meals.
And thanks to the fibrous cell wall, it’s thought our bodies don’t absorb 20 to 25 percent of the calories in nuts.
Toronto-based private dietitian Leslie Beck is director of food and nutrition at Medcan. Follow him on X @LeslieBeckRD