This article was first published on Huxiu's health and anti-aging public account "Jiuye Dao Research". The header image is from Pixabay. The full text is approximately 5,400 words.
For many ordinary people, the term "metabolism" is quite abstract and all-encompassing. In Professor Song's book, there are numerous cases of achieving a healthy state through dietary adjustments, and we had an in-depth discussion with her about the confusion and possible misconceptions that ordinary people have about the term "metabolism".
This is the third conversation between "Jiuye Dao" and Professor Song Jun. The article focuses on "misconception correction" to avoid pitfalls. You will read:
Can a healthy diet replace medical treatment?
Is there a necessary connection between obesity or being overweight and metabolic problems?
The advent of technological advancements has led to faster weight loss methods, so do diet, cooking, and metabolism still have a purpose?
Is it necessary to master all the knowledge details involved in popular science books on health?
Jiuye Dao Team
Song Jun (Director and Professor of Food and Nutrition Hygiene, Shanghai Municipal Center for Disease Control and Prevention)
In the introduction to your book *My Blood Sugar, My Call* (*Blood Sugar*), you mentioned a pre-diabetic patient who, without taking any medication, managed to bring their blood sugar and blood pressure back to normal levels through dietary adjustments, with your help and guidance. Does this suggest that we can resolve most or even all blood sugar and blood pressure abnormalities through dietary adjustments alone? Or, which individuals are suitable for achieving this goal through dietary therapy alone?
I want to use this question to clarify one thing: just because there's a case in the book where someone recovered very well through diet and lifestyle, it doesn't mean we can infer that "diet can replace medicine". That's not the point I wanted to convey by writing this book.
It can be understood this way: diet and lifestyle are the foundation, and medication is an important tool we use at different stages. Whether to only repair the foundation or to use medication at the same time depends on the individual's disease stage, blood sugar and blood pressure levels, pancreatic function, and whether there are risks to target organs such as the heart, brain, and kidneys.
Why was the pre-diabetic patient able to bring both blood sugar and blood pressure back under control without medication? The pre-diabetic stage is a critical window period where lifestyle interventions have extremely high value.
Large-scale diabetes prevention studies have shown that intensified lifestyle interventions can significantly reduce the risk of progressing from pre-diabetes to type 2 diabetes;
The 2026 ADA (American Diabetes Association) guidelines also take this approach, with structured lifestyle interventions as the cornerstone of diabetes management, a consistent theme throughout.
Moreover, blood sugar and blood pressure are not two completely isolated issues, as factors such as central obesity, insulin resistance, dietary structure, sodium intake, lack of exercise, and sleep can simultaneously affect both.
So when people's lifestyles truly change, they often find their blood sugar drops, waist circumference shrinks, and blood pressure improves as well. This isn't a case of one meal treating two conditions—rather, the shared metabolic environment behind these several indicators has shifted.
However, boundaries must be clearly defined.
If a diagnosis of hyperglycemia has been clearly made, or obvious complications have appeared, or pancreatic function is insufficient; if blood pressure remains high, reaching a level that requires medication, or has combined with high-risk conditions such as cardiovascular or kidney disease, it is recommended to follow the doctor's advice.
However, it is also recommended to implement effective lifestyle management interventions, and the earlier diet, exercise, sleep, and weight - these underlying factors - are adjusted, the more space the body will have.
I have always held the view that medication can help us control today's risks, while lifestyle changes are what alter the environment that generates risks for tomorrow.
These two things are not rivals, but rather partners.
You mentioned in the second chapter of "Blood Sugar" that "overweight and obesity often lead to insulin resistance." Currently, more than half of Chinese adults are facing overweight or obesity problems, can it be said that if they do not intervene in their lifestyle, they are likely to face insulin resistance or even diabetes problems?
Being overweight or obese does not necessarily mean insulin resistance, and it does not necessarily mean developing diabetes in the future; however, it does serve as a reminder that half of the population is overweight or obese, half of adults have excessive waist circumference, and half of adults have insulin resistance, with some overlap between these three groups, and this large group of people is entering a region with significantly increased metabolic risk.
More than half of Chinese people are overweight or obese, according to the "China Resident Nutrition and Chronic Disease Status Report (2020)". The report shows that 34.3% of Chinese residents aged 18 and above are overweight, and 16.4% are obese, totaling 50.7%.
The National Health Commission later released the "Obesity Diagnosis and Treatment Guidelines (2024 Edition)", which clearly states that obesity is one of the major causes of type 2 diabetes, and the higher the degree of obesity, the greater the risk of prediabetes and type 2 diabetes.
But I especially don't want everyone to hear this and become anxious in another way: "I'm fat, so my metabolism must be bad."
It's not like that.
In my actual observations, I have seen very overweight individuals with normal blood sugar and insulin responses, as well as young people with a BMI of less than 18 who have already developed significant insulin resistance. Therefore, I have always emphasized that body weight is an external appearance, while insulin resistance is an internal bodily state.
What is truly worth being vigilant about is when people, especially those with increasing waistlines, visceral fat, and fatty liver, also experience postprandial somnolence, abnormal blood sugar and lipid levels, and elevated blood pressure. Because at this point, what we are seeing is no longer just "obesity," but rather changes in fat storage location, energy utilization, and insulin sensitivity.
The National Health Commission's "Obesity Diagnosis and Treatment Guidelines (2024 Edition)" contains a set of noteworthy data: among the obese population, the incidence rates of pre-diabetes and type 2 diabetes are 43.1% and 23.0%, respectively.
The real upgrade for "weight management" today should be this: the goal isn't to make half the country thin, but to identify as early as possible whose bodies are already struggling to process the energy they consume each day.
If lifestyle interventions—diet composition, eating patterns, exercise, sleep—are adopted at this stage, what we're managing isn't just the kilograms on the scale today, but working to delay or even halt the progression from overweight and obesity to insulin resistance, then to prediabetes, and ultimately to type 2 diabetes.
So I say: obesity is not a verdict for diabetes, but a risk bill sent in advance by the body. The earlier we understand it, the more things we can change.
Most people can't recall improving their metabolism through diet, instead opting for weight loss injections when they're overweight and muscle-building injections when they lack muscle. Are there really more convenient and direct options that can achieve the same effects as dieting?
This is a particularly timely issue.
We are entering an era where people are increasingly accustomed to "solving physical problems with technology." If you're overweight, you hope a single injection can help you lose weight; if you lack muscle, you hope there will be an injection in the future that can help you build muscle; if you sleep poorly, there's a drug for that; if you have high blood sugar, there's also a drug for that. The advancements in medical technology are certainly something to be happy about. However, while medication can alter a specific outcome in the body, it's difficult to recreate the metabolic environment that the body operates in every day.
For instance, weight loss drugs can work by affecting appetite, gastric emptying, and related hormonal pathways, allowing a person to eat less, lose weight, and even improve indicators such as blood sugar levels. These benefits are worthy of respect. However, if we stop to think about it: why did a person originally become fatter and fatter? Why do they always want to eat? Why do they have increasingly poor feelings of fullness? Why do they have less and less muscle? Why have sleep, stress, sedentary behavior, and daily meals become what they are today?
Bariatric surgery, such as gastrectomy, is a good example, as it can alter stomach capacity, gastrointestinal hormones and appetite, enabling a person to lose weight significantly in a relatively short period of time, and even improve blood sugar levels, which is a major advancement in modern medicine.
However, surgery does not eliminate the issue of lifestyle. In long-term follow-ups, we still see a portion of people experiencing weight gain again.
Why is that? Because surgery alters a part of the body's structure and physiological environment, but it cannot automatically establish a new diet, exercise habits, sleep rhythm, and relationship with food for the individual.
So, technology can give the body a second chance, but the road ahead still has to be walked by the body itself.
This is also why I have always emphasized the importance of diet.
It's not because food is more "advanced" than medicine, nor is it because natural things are necessarily better than medical technology, but rather because people eat three meals a day, over 1,000 meals a year, and these signals are constantly entering the body.
A single meal cannot determine your health, but meal after meal over the course of three, ten, or twenty years will gradually shape your body.
For instance, when it comes to muscles, even if there are drugs that can promote muscle growth in the future, it doesn't mean you will have good muscle function. Muscles require not only "quantity", but also strength, neural control, mitochondrial capability, blood flow, and actual daily use. What we need is not a few more kilograms of tissue in our body, but rather muscles that can still lift us out of a chair when we are 70 or 80 years old.
I am not opposed to new technology, and I even look forward to medicine continually developing better tools.
What I oppose is an illusion: the notion that after technological advancements, we can outsource our bodies.
The body is not a car, where replacing a faulty part can fix the problem. It is an intelligent organism that constantly adapts to your diet, sleep, exercise, stress, and environment every day.
I think the best health management in the future is not a choice between medication and lifestyle, but rather medicine helps us overcome dangers when necessary, and lifestyle provides the body with a better daily operating environment.
Medicine can become increasingly advanced, but no advanced technology can take our place in eating the three meals a day that make up a lifetime.
I think this point will still be relevant in twenty years.
For ordinary people, metabolism is a vague term, and blood sugar itself is also an important indicator of metabolism, so how can we explain the importance of metabolism in one sentence to make it understandable to the general public?
Metabolism refers to the body's ability to convert the food you eat every day into vitality, rather than a burden.
We eat every day, and the same bowl of rice is consumed, but some people can quickly transport glucose into their muscles and cells, converting it into energy for walking, thinking, and working today. Others, however, need to secrete more and more insulin for their blood sugar to decrease, and excess energy will slowly accumulate in the liver and fat tissues, causing their waistline to expand.
So I think blood sugar is more like a "result" that we can see, while metabolism is the process and ability of the entire body to handle energy behind this result.
This is also why having normal blood sugar levels does not necessarily mean that metabolism is not a problem. Sometimes the body has to work very hard with insulin to keep blood sugar within a normal range. Normal numbers do not mean the body is not overworking.
If you already have abnormal blood sugar, pre-diabetes, or diabetes, or if someone in your family has blood sugar problems, I suggest reading "Blood Sugar" first. It's more like a handy reference book and dictionary that helps you understand the relationship between blood sugar, insulin, insulin resistance, and your daily meals.
If your blood sugar levels are currently fine, but you've started to experience increased waist circumference, fatty liver, abnormal uric acid levels, drowsiness after meals, poor sleep, or decreased energy, or if you're concerned about how to slow down your aging process over the next ten to twenty years, then you can start with "Metabolism".
If you have both, I suggest: first use "Blood Sugar" to learn how to read the signals sent by your body, then use "Metabolism" to understand why these signals occur.
"Blood Sugar" solves the problem of "how to understand myself", while "Metabolism" continues to solve the problem of "why I became like this and what to do next".
So they are not two separate approaches, but rather two perspectives on the same path.
Blood sugar is a window through which we see the body; metabolism is the world behind that window, operating day and night.
The two books, "Blood Sugar" and "Metabolism", delve into the effects and proper consumption methods of various nutritional components. I believe the biggest difference between the ideas and arguments presented in the two books is that they approach the topic from different perspectives, with "Blood Sugar" focusing on the impact of blood sugar levels on the body and "Metabolism" exploring the broader concept of metabolic function and its relationship to overall health.
"Blood Sugar" teaches readers to "understand blood sugar," while "Metabolism" probes why blood sugar has become what it is today.
When I wrote my first book, "My Blood Sugar, My Control," I was faced with a very real problem: many people, upon seeing high blood sugar levels, would immediately think "I must stop eating sugar" or "I need to cut back on staple foods," but in reality, they had no idea why their blood sugar was high, which meal was the problem, or when their body had lost balance.
So the first book is more like a dictionary, opening the window to blood sugar. I hope everyone can understand that the root cause is insulin resistance, and we can start to understand our own bodies through our daily meals, by observing the changes before and after meals. Blood sugar is not just a cold, isolated number, but rather the feedback our body gives us every day.
"My Blood Sugar, My Control", written by Song Jun and Sun Yueyang, was published by CITIC Press in July 2023.
However, after completing the first book and working on more and more cases, I found that I still had to keep moving forward.
I've seen very overweight people with decent blood sugar levels, and young women with a BMI of less than 18 who already have insulin resistance; some people's blood sugar levels haven't even exceeded the standard yet, but they're already experiencing changes in fatty liver, uric acid, waist circumference, sleep, and energy.
At this point, if we are still only focusing on blood sugar, it will be too late and too narrow.
So with "My Metabolism, My Way", I want to discuss a larger bodily system: the root is still insulin resistance, but with different people and different foods, how the pancreas reacts, how the liver processes, whether the muscles can take in the energy, why fat is stored, how the kidneys excrete, and how sleep, stress, hormones, and inflammation are all involved.
In other words, the second book moves from an indicator to a system, and continues to explore why things have developed step by step from "what has happened" to "why the body has ended up this way".
So the real relationship between the two books is not that the first one teaches you to control sugar and the second one teaches you to lose weight or resist aging.
Instead, the first book is about understanding the body from blood sugar and insulin, and the second book is about reunderstanding the body from metabolism and insulin. If there is a third book, I hope everyone can "see the body".
And in the end, they all point to the same thing: what we manage should not be just a number, but the body's own ability to maintain balance, utilize energy, and recover health.
This is also something I have wanted to tell everyone more and more over the past few years:
Don't wait until your body is really sick before you start managing your health.
The books "Blood Sugar" and "Metabolism" contain a large number of highly credible cases and have a very complex system, so do ordinary people need to fully grasp all the details. How can these health science popularization contents be put into practice?
I actually don't hope that after readers finish these two books, they will feel that they still need to pursue a degree in nutrition.
The book is written to be relatively comprehensive because I hope that when you encounter a specific problem, it can serve as a user manual that you can keep at home, and you know where to find the answers. However, in real life, it's not necessary to memorize all the knowledge.
I have always believed that health education ultimately needs to achieve a transformation: it's not about filling our brains with medical knowledge, but about turning that knowledge into daily habits that can be practiced without much thought.
"My Metabolism, My Rules", written by Song Jun, Bu Na, and others, published by CITIC Press in July 2026
For instance, you don't need to memorize all the pathways of insulin, but you can learn to observe: do I feel particularly sleepy after this meal? Do I get hungry again after two hours? Is my waistline getting bigger? Are my blood sugar levels fluctuating wildly?
You don't need to remember the GI, II, or AGE of every food, or the amount of nutrients per 100 grams. When it's time to eat, just focus on getting a few key things right: eat real food, have vegetables, protein, and a moderate amount of staples in each meal, eat regularly, chew slowly, drink enough water, and then observe your body's feedback.
This is also why I have always emphasized "thousand people, thousand sugars". Health management is not about taking a standard answer from a book and applying it to everyone, but rather establishing a basic framework and then adjusting it according to one's age, physical condition, lifestyle, and bodily feedback.
So I hope everyone reads these two books, not to say after finishing them, "Teacher Song, I've finally memorized everything." But rather, one day when sitting at the dinner table, they naturally know how to balance their meal; when their body undergoes changes, they can realize, "Oh, my body is sending me signals."
I think it is at this point that popular science education has truly been completed.
The highest level of health management is not about knowing more, but about making the right choices gradually become a daily routine that requires no willpower.
Of course, I've been thinking about a problem myself: although the first two books have tried to simplify complex medical knowledge, for ordinary people, it still requires "reading" and "understanding". If there's a third book, I'd really like to make it into a comic.
The human body itself is a fascinating story. Why insulin becomes increasingly exhausted, why the liver releases sugar in the middle of the night, why muscles sometimes refuse to "accept sugar", and why a person can eat a lot yet still feel hungry... if these things can be "seen", it may be easier to understand than explaining them ten times.
The best popular science is not about teaching ordinary people medicine, but about teaching medicine to finally speak the language of ordinary people.
Allowing someone with no medical background to read it on the subway, flip through it before bed, or even read it with their child, and suddenly realize: "It turns out my body is doing these things every day."