Understanding Nutrition Myths
Episode #8 of the course How to live a healthy lifestyle by FutureLearn
The World Health Organization suggests that over 1.4 billion people worldwide are overweight or obese, and dieting is a hugely popular industry in Western society today, with millions of dollars spent every year on gym memberships, weight loss supplements, and dieting books and magazines. Every year, a fashionable diet comes out that promises a beach body in a matter of weeks, yet these diets are often not supported by research data.
Diets work by restricting calorie intake, forcing the body to burn more energy than it takes in each day. Yet by limiting calorie intake, our bodies go into defense mode, protecting our existing body weight and sending out physiological signals to initiate the feeling of hunger. We might be able to battle against these hunger pangs in the short term, but scientific data on dieting trends shows that people typically revert to old eating habits in the long term and often end up putting on even more weight.
No carb diets
Diets that eliminate or severely reduce major food groups from our food choices have been popular over the past decade. The Atkins diet is one such diet that eliminates carbohydrates. Found in many of our day-to-day food staples, from starchy foods such as potatoes and pasta to fruits and vegetables, carbohydrates are the body’s main (and preferred) source of energy, and all food we eat is broken down into single units of glucose (a carbohydrate in its simplest form) to use for energy. Energy is used not only to help us perform daily activities, but also on a cellular level to keep our body systems functioning. Eliminating this major macronutrient will probably make you lose weight, but it can also make you feel weak and lethargic, making the diet difficult to stick to in the long term. Taken to extremes, no-carb diets can also put your body’s organ systems (such as the liver) under extra strain as the body is forced to manufacture the glucose it needs from fats and proteins.
The diet that does work
While diets that eliminate major food groups or severely restrict calorie intake have been debunked by scientists, eating plans that monitor the composition of meals have been credited. The three macronutrients (carbohydrates, protein, and fat) each have different effects on our appetite, and understanding the composition of these macronutrients on our plate can be very useful for when we want to eat less but still feel full. Per gram, protein contains the same number of calories as carbohydrates, yet protein has been shown to boost satiety levels—how full we feel—meaning we can eat less and still feel satisfied. Studies show that high-protein, moderate-carbohydrate diets (30% protein, 30% fat, and 40% carbohydrates) can help people achieve and maintain weight loss.
Recommended free course
“The China Study: The Most Comprehensive Study of Nutrition Ever Conducted and the Startling Implications for Diet, Weight Loss and Long-Term Health” by Thomas M. Campbell II, T. Colin Campbell
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