Is Sugar Really the Problem? The Research, the History, and the Honest Answer
Written by Rishi Bhojnagarwala
Medically Reviewed by Dr. Hetal Pal, PhD in Nutrition Science
Sugar has a GI of 100 in your hospital drip and a reputation as a dietary villain. Both cannot be true. Here is the full story.
The Glucose Drip Nobody Talks About
Here is a fact that gets remarkably little attention in the sugar debate.
When you are admitted to a hospital in a medical emergency — dehydration, low blood pressure, post-surgery recovery, metabolic crisis — the standard intravenous treatment is a dextrose solution. Dextrose and water. Glucose in its purest form. Delivered directly into your bloodstream, bypassing digestion entirely.
The glycaemic index of dextrose is 100. It is the reference point against which all other carbohydrates are measured. Table sugar — sucrose — has a GI of approximately 65 to 72. The thing doctors give you in a medical emergency is more glycaemically aggressive than anything you would encounter in your kitchen.
When a person with diabetes goes into hypoglycaemia — dangerously low blood sugar — the clinical treatment protocol is fast-acting simple carbohydrates. Fruit juice. Glucose tablets. A regular biscuit or cookie made with table sugar. The food they spend the rest of their life avoiding becomes the prescribed emergency treatment because nothing raises blood glucose faster or more reliably.
At kilometre five of a morning run, when muscle glycogen is depleted and performance is dropping, elite athletes and amateur runners alike reach for simple sugar — gels, sports drinks, glucose tablets. The slow-release energy of a date or a whole grain snack is exactly wrong at this moment. You need simple sugar absorbed rapidly. The body is asking for it.
The molecule that your hospital gives you intravenously, that saves a diabetic in crisis, and that powers athletic performance is the same molecule that has been blamed for the global obesity epidemic.
Something about this narrative does not add up. Let us look at what actually happened.
The Sugar Industry's Most Successful Campaign
In 1972 a British physiologist and nutritionist named John Yudkin published a book called Pure White and Deadly. Yudkin had spent two decades researching the relationship between sugar consumption and chronic disease. His conclusion was that sucrose — specifically its fructose component — was the primary dietary driver of obesity, heart disease, and metabolic syndrome.
He was largely dismissed, professionally discredited, and largely forgotten.
At the same time, an American physiologist named Ancel Keys was building what would become the most influential nutritional hypothesis of the twentieth century — that dietary saturated fat, not sugar, was the primary cause of cardiovascular disease. His landmark Seven Countries Study, published in various forms through the 1950s and 1970s, shaped dietary guidelines across the Western world and eventually across India.
What the full story reveals is considerably less flattering to the nutrition establishment.
In 2016 a team of researchers at the University of California San Francisco published a peer-reviewed analysis in JAMA Internal Medicine documenting internal documents from the Sugar Research Foundation — the lobbying body of the American sugar industry — from the 1960s. These documents showed that the Sugar Research Foundation had identified the emerging scientific concern about sugar and heart disease as a threat, and had funded research specifically designed to shift scientific and public attention toward dietary fat as the culprit.
The researchers they funded published reviews in the New England Journal of Medicine in 1967 that downplayed sugar's role in cardiovascular disease and emphasised fat's role. The funding source was not disclosed. The lead author later went on to become a senior nutrition policy official, directly influencing the US dietary guidelines that subsequently shaped global nutrition recommendations including those in India.
The demonisation of fat that followed — the low-fat diet movement of the 1980s and 1990s — had a direct and measurable consequence. When manufacturers reformulated products to be lower in fat, they needed to maintain palatability. Fat carries flavour and provides satiety. Remove it, and food tastes flat and unsatisfying.
The solution was sugar. The food industry added sugar to low-fat yoghurt, fat-free cookies, reduced-fat salad dressings, and hundreds of other products to compensate for the flavour and texture that fat removal had eliminated. The low-fat era was, nutritionally, a high-sugar era — and it was built on the foundation of research that had been deliberately shaped to protect a commercial interest.
What Sugar Actually Is
The word sugar covers a family of related molecules that behave differently in the body and are found in very different natural sources.
Glucose is the body's primary fuel. Every carbohydrate you eat is ultimately converted to glucose before your cells can use it. It is found in most plant foods and is the dominant sugar in starchy vegetables and grains.
Fructose is the sugar found primarily in fruit. It is metabolised differently from glucose — processed almost entirely by the liver rather than available for immediate cellular energy. In the quantities found in whole fruit, alongside fibre, water, and micronutrients, this is not a problem. In the quantities found in high-fructose corn syrup added to processed foods and beverages, the liver processing becomes a concern.
Sucrose is table sugar — one glucose molecule bonded to one fructose molecule. It is what you add to chai, what is in mithai, what is in your biscuits. When digested, it splits into equal parts glucose and fructose.
Lactose is the sugar in milk. Maltose is the sugar produced when starch breaks down. Galactose is a component of lactose. All sugars, all processed by the body through the same fundamental metabolic pathways.
The reason sugarcane and corn are the dominant commercial sources of sugar is purely economic. Extracting sucrose from sugarcane is extraordinarily efficient — a mature sugarcane plant is approximately 12 to 15 percent sucrose by weight, and the extraction process is well-established and inexpensive. If the same quantity of sucrose were extracted from apples — technically possible — it would cost many times more and be chemically identical. The apple is healthy not because its sugar is different sugar but because it comes with fibre, water, vitamins, and a physical form that naturally limits how much you consume.
You can eat one apple and feel reasonably satisfied. You cannot drink an equivalent quantity of apple juice — processed to remove the fibre — without consuming far more calories with far less satiety.
Sugar in Context: Why the Combination Matters
Almost no one eats sugar in isolation. The sugar we consume in real food is almost always combined with other macronutrients that dramatically modify how the body responds to it.
Sugar combined with fat — as in chocolate, mithai made with ghee and dairy, or most Indian sweets — produces a significantly lower glycaemic response than sugar alone. Fat slows gastric emptying, which means glucose enters the bloodstream more slowly and produces a more moderate insulin response.
Sugar combined with protein — as in dairy-based sweets, payasam, or kheer — produces a similar moderating effect. Protein stimulates the release of hormones that slow digestion and increase satiety.
Sugar combined with fibre — as in whole fruit, or in foods containing whole grains — produces the slowest and most moderate glycaemic response of all.
The glycaemic index of sucrose alone is approximately 65. The glycaemic index of milk chocolate — which contains sugar, fat, and some fibre from cocoa — is approximately 40 to 45. The glycaemic index of whole fruit containing equivalent amounts of fructose is typically 30 to 40.
The sugar in a kaju katli, eaten after a meal that included dal, roti, and vegetables, is processed by a body that has already moderated its insulin response through the fibre and protein of the preceding meal. This is meaningfully different from drinking a bottle of a sugar-sweetened beverage on an empty stomach.
Context is everything. The molecule is not the problem.
Did Sugar Actually Cause the Diabetes Epidemic?
This is the question that produces the most heat in nutritional science, and the honest answer is: it is significantly more complicated than the popular narrative suggests.
Type 2 diabetes is a condition of insulin resistance — the body's cells become less responsive to insulin's signal to absorb glucose from the bloodstream. Blood glucose remains elevated. Over time this elevation damages blood vessels, nerves, and organs.
The question is what causes insulin resistance. The popular narrative says sugar. The research says something more complex.
Insulin resistance is strongly correlated with excess body fat — particularly visceral fat around the abdominal organs. It is correlated with physical inactivity, chronic sleep deprivation, chronic psychological stress, specific genetic variants, certain medications, and the overall pattern of dietary intake over time rather than any single food.
Excess caloric consumption of any kind — not specifically sugar — produces the weight gain and metabolic disruption that precedes insulin resistance. Populations eating high-carbohydrate diets including significant amounts of natural sugars — traditional Japanese populations consuming white rice, traditional Indian rural populations consuming jaggery and sugarcane — historically had very low rates of type 2 diabetes. The diabetes rates in these populations increased as their diets modernised — but the modernisation included processed foods, sedentary lifestyles, increased stress, and sleep disruption alongside increased sugar. Isolating sugar as the single causal factor in this context is not supportable by the evidence.
Sugar is unquestionably a problem for a person who already has type 2 diabetes. Their insulin response is impaired and rapid increases in blood glucose cause harm. But the causal chain that led to that diabetes almost certainly involved total caloric excess, weight gain, inactivity, and genetic predisposition — not sugar as an isolated villain.
What Actually Caused the Problem
The honest account of how sugar became the dietary villain is partly a story of genuine science, partly a story of commercial manipulation, and mostly a story of overconsumption.
The genuine science: fructose in large quantities — particularly as high-fructose corn syrup in beverages — is metabolised in ways that can contribute to fatty liver disease, insulin resistance, and elevated triglycerides. This is real and has been demonstrated in controlled research.
The commercial manipulation: the sugar industry funded research designed to shift blame to fat, which led to low-fat dietary guidelines, which led to high-sugar reformulated processed foods, which dramatically increased population sugar consumption in ways that had nothing to do with people choosing to eat more sugar.
The overconsumption: the human body evolved in an environment where concentrated sweetness was rare, seasonal, and limited by the natural structure of the foods that contained it. A piece of fruit in season, available for a few weeks, eaten until satiated and then unavailable. The modern food environment delivers concentrated sweetness in unlimited quantities, engineered to bypass satiety signals, at low cost and high availability. The problem is not the molecule. It is the dose.
A teaspoon of sugar in your morning chai is metabolically insignificant. The same molecule delivered continuously through the day in flavoured beverages, sweetened yoghurts, packaged snacks, and ultra-processed foods crosses into territory where the quantity genuinely matters.
The Practical Answer
Unless you have diabetes or a relevant genetic condition, sugar is not your enemy.
The mithai at Diwali is not going to give you diabetes. The chai you drink every morning is not going to kill you. The gulab jamun after dinner is not the reason your weight is not where you want it.
What matters is total caloric intake over time. What matters is the overall pattern — how much you eat, how active you are, how much you sleep, how you manage stress.
Sugar contributes to excess caloric intake most powerfully when it comes embedded in ultra-processed foods that are engineered to be eaten in large quantities — not when it comes in a katori of kheer or two pieces of mithai at a family occasion.
Know what you eat. Know how much. Enjoy the mithai.
That is still the whole answer.
About Caddy Caddy tracks your actual food — including the gulab jamun — and gives you one honest daily score. Score 8 means you are on track regardless of what you ate. No food is forbidden. No ingredient is banned. Just awareness, and one number. Visit getcaddy.ai