Sucrose

Sucrose is ordinary table sugar, made of one glucose and one fructose unit. It occurs naturally in sugar cane, sugar beet, fruit and some vegetables, and is added in large amounts to drinks, desserts and processed foods.

What is it?

Sucrose is a disaccharide: glucose and fructose joined together. The body splits it with the enzyme sucrase in the small intestine, then absorbs the two single sugars. White sugar, brown sugar, raw and muscovado sugar, palm sugar (gula melaka), coconut sugar, icing sugar and cane syrup are all mostly sucrose.

Naturally occurring sucrose in whole fruit and vegetables comes with fibre, water and nutrients. Sucrose added to foods and drinks is an added sugar, the type to limit.

What it does

1. Provides energy at about 4 kilocalories per gram
2. Adds sweetness, texture and preservation to foods
3. Has a medium glycaemic index (about 65), between fructose and glucose

Food sources

Table and cane sugar, brown sugar, palm sugar and syrups; sweets, chocolate, cakes, biscuits, ice cream, desserts, sweetened drinks, sauces, jams and breakfast cereals. Naturally in sugarcane, dates, pineapple, mango, carrots and sweet potato in smaller amounts.

Singapore food examples

1. Kopi and teh with sugar or condensed milk — ask for "kosong" (no sugar) or "siew dai" (less sweet)
2. Gula melaka (palm sugar) in kueh, chendol and ondeh-ondeh
3. Kaya, sweet sauces and sweetened soy milk
4. Bubble tea, canned drinks and sugarcane juice
5. Desserts — ice kacang, bubur cha cha, pineapple tarts
6. Look for the Nutri-Grade label on drinks and the Healthier Choice symbol on packaged foods

How much do I need?

Singapore's dietary guidelines advise that added sugar — most of which is sucrose — provide no more than 10 percent of daily energy, about 10 teaspoons (around 50 g) on a 2,000-kilocalorie diet, and about 5 teaspoons (25 g) is even better. One teaspoon is about 5 g. See Singapore's dietary guidelines for adults (HealthHub). There is no minimum requirement for sucrose.

Low intake and deficiency

There is no deficiency; the body does not need sucrose, and gets glucose from starch and other foods.

Too much and safety

A high intake of sucrose, particularly in drinks, adds energy without making you feel full and is linked to weight gain, tooth decay, fatty liver disease, type 2 diabetes and heart disease. Sucrose is considered the most decay-causing common sugar, because oral bacteria ferment it readily.

Brown sugar, palm sugar, honey and syrups are not meaningfully healthier than white sugar: they are still added sugar.

Absorption and bioavailability

Sucrose is split by sucrase on the lining of the small intestine into glucose and fructose, which are then absorbed. Sucrase deficiency is rare (congenital sucrase-isomaltase deficiency) and causes diarrhoea and bloating after sugar-containing meals.

Liquid sucrose is absorbed quickly and raises blood glucose fastest; eating sugar with fibre, protein and fat slows it.

Connection to daily life

1. Dental health: brush with fluoride toothpaste and limit how often you have sweet snacks and drinks
2. Energy: sugar peaks can be followed by dips; regular meals with protein and fibre keep energy steadier
3. Sleep and stress: sugary foods late in the day may disturb sleep, and stress eating often goes for sweets — see Sleep and Stress
4. Related: see Sugars, Fructose and Glucose

Sources: 1. HealthHub Singapore — Dietary guidelines for adults: https://www.healthhub.sg/well-being-and-lifestyle/food-diet-and-nutrition/dietary_guidelines_adults 2. HealthHub Singapore — Recommended Dietary Allowances: https://www.healthhub.sg/well-being-and-lifestyle/food-diet-and-nutrition/recommended_dietary_allowances 3. Health Promotion Board — Singapore Food Insights Database (SG FoodID): https://www.hpb.gov.sg/healthy-living/food-and-beverage/sgfoodid/ 4. FAO/INFOODS — Food composition tables and databases: https://www.fao.org/food-composition/tables-and-databases/en/ 5. National Academies of Sciences, Engineering, and Medicine — Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (2005)