Sweet and Deadly: Beware Our Sweet Little Liver | Grandma Kouzi
In 1972, the British scientist John Yudkin published a book titled Pure, White and Deadly. The star of that book was sugar—pure, pristine white sugar. The star of this little essay is also sugar—sweet sugar.
The “sugar” referred to here encompasses sugar, confectionery, and added sugar in food products. Its disguises on the ingredients list might be sucrose, granulated white sugar, high-fructose corn syrup, honey, maltose, glucose syrup, and so on.
The latest US Dietary Guidelines, released in January 2026, emphasise that “sugar is not considered part of a healthy or nutritious diet”. I wholeheartedly agree, but I have doubts about feasibility.
I. Why Sugar Is Essential Yet Unnecessary
Blood glucose is the body’s most fundamental source of energy, just as petrol is to an engine. An engine runs on petrol; human life runs on sugar. I have taken part in the Hong Kong 100 km endurance walk and the 66 km Mount Tai Loop Marathon, where sports drinks containing sugar and electrolytes are an essential supply at every checkpoint. But this can easily lead to a misconception—the idea that sugar is important, and therefore eating sugar must be important too. In fact, it is not.
Chinese people often greet one another with the question, “Have you eaten?” A meal is our most everyday source of energy, consisting mainly of starchy foods. Starch, however, is a high-molecular-weight carbohydrate made up of multiple monosaccharide molecules linked by glycosidic bonds—a kind of sugar that is not sweet. Composed of hundreds or thousands of glucose units polymerised together, starch molecules are simply too large to bind effectively with the sweet taste receptors on the tongue, and so our taste buds cannot directly perceive them as “sweet”.
Therefore, rice and steamed buns are sugar, and so are potatoes and taro. But this kind of sugar is a polysaccharide (such as starch and cellulose), which, along with monosaccharides (such as glucose and fructose) and disaccharides (such as sucrose and maltose), belongs to the sugar family.
The process of eating and digesting is, in essence, a series of chemical reactions within the body that hydrolyses polysaccharides into the monosaccharides the body needs. The body uses enzymes as scissors to cut the “sugar chain” of starch. The scissors are “salivary amylase” before they enter the stomach, and “pancreatic amylase” after the stomach delivers them to the small intestine. In the end, the polysaccharide is snipped down to its smallest unit—monosaccharides that can no longer be hydrolysed—and they enter the bloodstream. Sugar, then, is an essential substance the body produces on its own, without needing to be consumed.
Although blood sugar is absolutely vital to human life, one need not eat that sweet kind of sugar.
II. Sugar Is Everywhere
A few years ago, while living in Taiwan, someone conducted a survey of supermarket food shelves. Remove all sugar and every product with added sugar, and barely 20 per cent would survive.
Sugar is now deeply embedded in modern life.
All sweetened drinks, filled confectionery, chocolate, and pastries are high in sugar. Ice lollies and ice cream are sugar-and-fat bombs through and through. Instant puddings, sweetened tofu pudding, and instant milk tea contain equally astonishing amounts of sugar. Ready-to-eat cereals such as instant oats and cereal bars may look healthy but are just as high in sugar. Then there are the hidden-sugar heavyweights: crisps, prawn crackers, rice crackers, and other savoury puffed snacks all contain added sugar, and so do flavoured nuts and most ready-to-eat meat products, where sugar is added to boost flavour.
Some products even trumpet “Sugar-Free ××” or “No Added Sugar ××” in large print, yet a close look at the ingredients list reveals the trick: the product merely has “no added sucrose”—replaced instead by high-fructose corn syrup, honey, maltose, and glucose syrup, all of which are still sugar.
Moreover, condiments are another hotspot for hidden sugar. Salad dressing is often high in both sugar and fat—a true hidden-sugar bomb. Tomato ketchup, sweet chilli sauce, barbecue sauce, instant noodle seasoning packets, and instant soup bases all commonly contain sugar. Oyster sauce may not contain oysters, but it will certainly contain sugar. Even flavoured vinegar and dark soy sauce contain sugar—the darker the colour, the more sugar added…
III. A Liver-Overloading Lifestyle
The most common monosaccharides are glucose and fructose, the two components of sucrose. They frequently appear together, yet they are almost entirely different kinds of monosaccharide, with wholly distinct structures and metabolic pathways.
Glucose comes from starchy foods such as grains and root vegetables. It is an aldose that can be directly utilised by cells throughout the body. What is commonly called “blood sugar” refers to glucose in the blood; its uptake is insulin-dependent, its glycaemic index is high, and overconsumption leads to diabetes.
Fructose, on the other hand, is a ketose commonly found in fruit, honey, and corn syrup. Its sweetness is roughly 1.2–1.7 times that of sucrose. Fructose is metabolised primarily in the liver without requiring insulin; excessive intake is directly converted into fat that accumulates in the liver, forming non-alcoholic fatty liver disease.
Although the human liver can metabolise up to 100 grams of sugar a day, the WHO recommends that adults keep their daily free sugar intake below 5 per cent of total energy intake (approximately 25 grams). Free sugars are monosaccharides (such as glucose and fructose) and disaccharides (such as sucrose or table sugar) added to foods and drinks by manufacturers, cooks, or consumers, as well as sugars naturally present in honey, syrups, fruit juices, and fruit juice concentrate.
The liver is one of the most vital organs in the human body, responsible for life-sustaining functions including metabolism, detoxification, bile secretion and excretion, synthesis, immune defence, storage, and blood regulation. It does not exist solely to process sugar. Each of these functions has many sub-functions; metabolism alone encompasses sugar metabolism, fat metabolism, and protein metabolism. We have only one sweet little liver for our entire life—we must use it wisely and must not reduce it to a one-way street for sugar metabolism.
Yet many people, every single day, push their liver to its very limits. A 500 ml bottle of cola or other sweetened drinks contains around 50 grams of sugar; add sweet milk tea, the various hidden-sugar snacks on supermarket shelves that are ready straight from the packet, added sugar in takeaway cooking, and a little alcohol on the side… every day is a liver-overloading ordeal.
The damage sugar inflicts on the body does not stop at the liver. A long-term high-sugar diet causes blood glucose to spike frequently, driving the pancreas to pump out large amounts of insulin continuously, eventually developing into type 2 diabetes.
Sugar also causes dyslipidaemia, elevated blood pressure, vascular inflammation, and atherosclerosis, significantly increasing the risk of coronary heart disease, myocardial infarction, and stroke. Sugar is a key factor driving the “fatty liver → diabetes → heart disease” chain.
IV. Why Sugar Is So Hard to Shake Off
Because children in modern society are drinking a kind of “liquor that never gets you drunk”—fructose—almost every single day.
Cases of non-alcoholic fatty liver disease are growing ever more common, striking children at younger and younger ages, because the sweets, pastries, and sugary drinks found everywhere soak their little livers in sugar water from infancy.
The latest US Dietary Guidelines, released in January 2026, emphasise that sugar is not considered part of a healthy or nutritious diet: “No amount of added sugar or non-nutritive sweetener is recommended; neither belongs to a healthy or nutritious diet.” The guidelines further advise completely avoiding added sugar during infancy and toddlerhood, and recommend that children aged 5–10 consume no added sugar whatsoever.
I agree, but I have doubts about feasibility. Beyond what I have already discussed—that added sugar is woven into four-fifths of the products on supermarket shelves—it is also because today’s children, steeped in sugary food from infancy, have had the Bliss Point write their dependence on sugar into the very fabric of their lives.
“People are not choosing nutrition; they are choosing a sensory experience. Sweetness is the fastest route to pleasure.”
These words come from none other than the renowned Howard Moskowitz, holder of a PhD in experimental psychology from Harvard University, who excels at applying mathematical models and statistical methods with precision to measure and analyse human sensory responses. His most celebrated achievement was the discovery in the 1970s of the “Bliss Point”—the perfect balance of sweetness, saltiness, and fat content (or crunch) in food. When a food’s taste stimulation hits just the right level, it triggers pleasure at the brain’s reward centre, to the point where “the more you eat, the more you crave, and you simply cannot stop.”
Moskowitz once put it this way: “The Bliss Point is that particular sensory food experience you love most, and it is primarily linked to sweetness.” Sugar and sweet things prompt the brain to release endorphin-like substances, producing pleasure and satisfaction. Once sugar content rises beyond a certain threshold, the Bliss Point is triggered—plainly put, addiction.
In the 1970s, the sweetness increasingly triggering humanity’s Bliss Point was no longer “sucrose” in the conventional sense, but “fructose.”
The fructose used in processed products is derived from industrially produced corn syrup. First, amylase hydrolyses starch to yield glucose syrup; then, glucose isomerase converts a portion of the glucose into fructose. The world’s cheapest starch, produced in the greatest volume, is genetically modified corn starch from the United States. The corn syrup obtained this way is staggeringly cheap.
Fructose’s metabolic pathway closely resembles that of alcohol—it is processed primarily in the liver, and excessive intake leads to fat accumulation, insulin resistance, and metabolic syndrome. Some therefore define it as a chronic, dose-dependent hepatotoxin.
Moskowitz also said: “Sugar is not the enemy—it is a tool. The problem lies not in sugar itself, but in the system that abuses it.” Marlboro, Coca-Cola, Pepsi, Nestlé, Kraft, and others have competed to launch ever-sweeter products, targeting children above all, engraving a dependence on sweetness into the lives of generation after generation.
V. How to Break Free from Sugar?
More and more people are now advocating a total ban on sugar. It is plainly not an essential nutrient for the human body, yet it is as harmful and addictive as a drug—especially fructose, used in vast quantities in sweetened drinks and even more harmful to children. Sugar has been carved into the lives of generation after generation since early childhood; to pull it out—how could that be easy.
To break free from sugar, first, refuse sweetened drinks. Second, neither buy confectionery and pastries for yourself nor gift them to others. Third, choose snacks wisely. Choose genuinely sugar-free options: plain sunflower seeds, peanuts, walnuts, cashews and pistachios are all good—if you can eat the fruit whole, never reach for a processed fruit product.
The ingredients list has its own traps. Beyond those already mentioned, watch out for disguises such as trehalose, invert sugar, maple syrup, agave syrup and fruit juice concentrate, as well as hidden sugars like maltodextrin and dextrin whose glycaemic index is even higher than granulated white sugar.
Aspartame, sucralose, acesulfame K, erythritol, steviol glycosides, mogrosides and other sugar substitutes are indeed sugar-free, but I will not touch them, because I cannot be sure whether they are harmful. When in doubt, reject. Sugar substitutes may stimulate appetite, indirectly leading to greater calorie intake. One further note of caution: zero sugar ≠ no sugar—the GB standard permits a label of “zero sugar” for products containing 0.5 g or less of sugar per 100 ml.
In the next post, I will share a few sugar-free and low-sugar snack recipes, using ordinary ingredients available in any supermarket, made at home with your children to create healthy, sweet treats. By taking matters into your own hands, you can strive to keep yourself safe in a world besieged by sugar.
Unless otherwise noted, all images in this article are provided by the author.
Edited by Xiaodan