In the first two episodes, we detailed what exactly the fat that people want to get rid of is, and the mechanisms of fat cells enlarging and shrinking. Today, we are finally going to talk about the topic that everyone cares about the most—how to plan a weight loss menu and how to eat to slim down. Hello everyone, I am Director Wang Yan from the Institute of Dietary Nutrition and Health Science at Wang University. Health is our greatest wealth, let’s manage it together.
This time, it took a lot of effort, preparing for the show “Science of Really Nice” three times longer than the last time. After all, obesity is the number one enemy faced by health experts around the world, with countless related literature and research, the pressure is really tremendous.
After researching several hypotheses of obesity and various dietary theories, reviewing dozens of authoritative studies, and interviewing experts and holding seminars in various fields, I finally have a more confident view on the matter of weight loss, which also greatly corrected my previous concepts about weight loss. However, before discussing weight loss, I feel it is necessary to first explain the current situation of obesity.
The World Health Organization has pointed out that by 2022, there were over 2.5 billion adults worldwide who were overweight, meaning those with a BMI over 25 accounted for 43% of all adults. Among them, over 890 million adults had a BMI over 30, meaning that less than 7 out of 1 persons had obesity, a number that doubled compared to 1990. People with obesity have a significantly increased risk of dying from cardiovascular diseases, diabetes, cancer, and neurological diseases.
If no measures are taken, it is estimated that by 2030, the global cost of overweight and obesity will reach $3 trillion annually, and by 2060, it will exceed $18 trillion. You may not have a clear idea of this figure, but you should know that the total annual budget of all countries in the world is approximately around 20 trillion. If this trend continues, governments will probably have to spend their income on healthcare, and other matters will be neglected.
Because of this, experts and scholars worldwide are striving to explore the fundamental reasons for the ongoing weight gain in humans, hoping to find a permanent solution, and the weight loss industry is growing along with this trend. Besides pharmaceutical companies and gyms, the most common are best-selling books on diets.
Foreign best-selling authors on diet and nutrition number in the hundreds, and each of them has published more than one book. Among the most popular works listed here, more than half have made it to the New York Times bestseller list. One book sold over 10 million copies, which is “Doctor Atkins’ Diet Revolution,” published by the late Dr. Robert Atkins in 1981, the pioneer of the popular low-carb diet.
In fact, the history of low-carb diets can be traced back to the 19th century when it was mainly used for diabetes patients and was not very popular. In the 20th century, people started calculating calorie intake to pursue aesthetics. At that time, it was well known that 1 gram of fat equals 9 calories while 1 gram of carbohydrates is only 4 calories.
So low-fat diets remained mainstream until the 1950s when scientists discovered a strong association between diets high in saturated fats and cholesterol and cardiovascular diseases. The medical community in the United States then began promoting low-fat diets. However, in the following decades, people’s weight continued to rise, and the incidence of cardiovascular diseases remained high.
When Dr. Atkins advised his patients to stop unhealthy sugary drinks and refined carbohydrates and switch to a diet rich in protein and fats like meat, fish, and nuts, and successfully helped many patients lose weight, his close to ketogenic diet gradually gained popularity in the United States, peaking in 2000, where about 1 in 11 Americans was following his diet.
In 2003, he passed away at the age of 72 due to a fall that resulted in a cerebral infarction. There were various opinions about the cause of his death at that time. A vegetarian advocacy committee sent the medical report to The Wall Street Journal, stating that he weighed as much as 117 kilograms and suffered from heart disease, congestive heart failure, and high blood pressure, among other conditions.
However, a doctor from his company came forward to refute these claims, stating that his pre-existing heart issues were actually a form of myocardial disease caused by a virus, not diet-caused cardiovascular diseases. If you were an American onlooker, whom would you believe? Due to his immense influence, a fierce debate was sparked at that time, and his diet gradually lost popularity after his passing, until the emergence of the next low-carb advocate, Gary Taubes.
Gary Taubes is a controversial science journalist who graduated from Harvard’s applied physics department and earned a master’s degree in aeronautical engineering from Stanford, later receiving a master’s degree in journalism from Columbia University, quite impressive. After graduation, he joined Discover magazine, focusing on physics-related topics at first before transitioning to medical and nutritional studies.
In 2007, he published a bestselling book, “Good Calories, Bad Calories,” arguing that refined carbohydrates such as flour and sugar are the culprits behind obesity, diabetes, heart diseases, and cancer. Since then, he has become a leading figure in anti-sugar and refined carbohydrate movements, writing many articles and publishing another book, “Why We Get Fat: And What to Do About It,” emphasizing that reducing carbohydrate intake can aid in weight loss. In 2012, he decided to do something significant.
He co-founded the Nutrition Science Initiative (NSI) with the well-known Dr. Peter Attia, establishing a non-profit organization. They claimed that it was a “Manhattan Project” aimed at ending obesity, with the core method being low-carb diets.
The primary funder of NSI was John Arnold, a senior executive at Enron, yes, that Enron. He pledged $40 million to sponsor NSI for carrying out substantial scientific research to address the obesity issue. They decided to hire world-class researchers to conduct four research projects to verify the effectiveness of low-carb diets for weight loss.
So they collaborated with David Ludwig, a nutrition professor at the Harvard T.H. Chan School of Public Health and an advocate of low-carb diets, to lead one of the research projects. Before proceeding with the experiments conducted by Professor Ludwig, let’s first explain the carbohydrate-insulin hypothesis he proposed, which is the current theoretical basis of low-carb diets. Professor Ludwig believes that the rising obesity prevalence is not primarily caused by the widely believed factor of caloric surplus leading to obesity, which is a misconception.
When you visit a weight loss clinic, a doctor will tell you that gaining weight is due to consuming more calories than you expend, and the excess calories are stored as fat. To lose weight, one must eat less and move more. However, Professor Ludwig argues that this view is incorrect.
He put forth the famous Carbohydrate-Insulin Model of Obesity (CIM), which posits that eating a large amount of high-glycemic index carbohydrates leads to an increase in postprandial insulin levels, promoting the entry of calorie sources such as blood sugar and free fatty acids into fat cells rather than supplying the tissues for use. Review the previous episode on fat flux for more details on how insulin stimulates fat synthesis and inhibits lipolysis mechanisms.
