Experts Debunk Three Common Diet Misconceptions
For the sake of health, many people follow various dietary adages. However, in this age of information overload, a flood of nutritional advice abounds. Beyond folk misconceptions, media misinformation, and misleading advertising, even some objective and impartial dietary advice is often misunderstood due to a lack of nutritional knowledge. Therefore, Professor Jiang Zhuoqin, a doctoral supervisor in the Department of Nutrition at the School of Public Health of Sun Yat-sen University, points out that consumers currently hold three major fundamental misconceptions about food.
Misconception 1: Overgeneralization
In understanding food, people often rely on experience, focusing on a single attribute of a food to form a deep-set judgment, thereby categorizing the food. For example, "fat causes obesity" or "eating more vegetables is beneficial to health." In fact, consuming too little fat or too many fruits and vegetables is harmful to the body. Many white-collar workers, in order to maintain their figure, consume large amounts of vegetables while reducing or eliminating meat and fish. This not only affects the body's intake and absorption of essential fatty acids and high-quality protein, leading to protein malnutrition, but also hinders the absorption of rich nutrients such as calcium, iron, and zinc from non-vegetarian foods.
Misconception 2: Throwing out the Baby with the Bathwater
People often refuse to eat a food simply because it contains a certain harmful substance, which is often unnecessary. For instance, many people recently have become terrified of trans fatty acids, treating foods containing them like venomous beasts, which is an overcorrected misunderstanding. Trans fatty acids mainly come from two sources: one is produced during the hydrogenation of vegetable oils, and the other is generated during the digestive process of ruminant animals. Trans fatty acids can be found in the meat and dairy products of cattle and sheep, and more than 40% of processed foods on the market contain them, making it nearly impossible to completely avoid them.
Misconception 3: Blindly Applying Standards
Various countries have set maximum residue limits for potentially harmful substances in food—the acceptable daily intake (ADI), which is the amount of a chemical substance that a person can ingest daily over a lifetime. Standards vary from country to country, and the main reason for this difference is not the advancement of nutritional science, but the differences in dietary structures. Some domestic citizens use Western standards as a guide for their daily diet, which Professor Jiang considers unscientific. For example, regarding the healthy intake of trans fatty acids, China has not yet established relevant standards. Professor Jiang believes that for Chinese residents, it is inappropriate to overemphasize trans fatty acids at this stage; controlling the total fat intake is clearly more important.
Image Source: Quanjing