{"id":50503,"date":"2026-06-05T20:31:52","date_gmt":"2026-06-05T15:01:52","guid":{"rendered":"https:\/\/blog.ultrahuman.com\/blog\/?p=50503"},"modified":"2026-06-05T20:31:54","modified_gmt":"2026-06-05T15:01:54","slug":"types-of-sugar-explained-how-each-one-affects-your-body","status":"publish","type":"post","link":"https:\/\/blog.ultrahuman.com\/blog\/types-of-sugar-explained-how-each-one-affects-your-body\/","title":{"rendered":"Types of Sugar Explained: How Each One Affects Your Body"},"content":{"rendered":"\n

“Sugar” on a food label isn’t one ingredient. The names you’ll see \u2014 glucose, fructose, sucrose, high-fructose corn syrup, lactose, and a long list of “-oses” and syrups \u2014 are different forms of sweet carbohydrate, and they don’t all behave the same way in your body. Some spike your blood sugar fast (glucose, maltose). Some bypass blood sugar but get processed by your liver \u2014 where high or chronic intake can build up over time (fructose, HFCS). Some are barely absorbed at all (sugar alcohols like erythritol). This guide walks through each common type of sugar, what it actually does in your body, and how to spot it on an ingredient list.<\/p>\n\n\n\n

The sugar chart at a glance<\/h2>\n\n\n\n
Sugar<\/th>Family<\/th>Made of<\/th>Glycemic index*<\/th>Where you find it<\/th><\/tr><\/thead>
Glucose<\/strong><\/td>Monosaccharide<\/td>Single unit<\/td>100 (reference)<\/td>Honey, dextrose, glucose syrup, fruit<\/td><\/tr>
Fructose<\/strong><\/td>Monosaccharide<\/td>Single unit<\/td>~19<\/td>Fruit, honey, agave, HFCS<\/td><\/tr>
Galactose<\/strong><\/td>Monosaccharide<\/td>Single unit<\/td>~20<\/td>Only from lactose digestion (dairy)<\/td><\/tr>
Sucrose<\/strong><\/td>Disaccharide<\/td>Glucose + fructose<\/td>~65<\/td>Table sugar, cane sugar, beet sugar<\/td><\/tr>
Lactose<\/strong><\/td>Disaccharide<\/td>Glucose + galactose<\/td>~46<\/td>Milk, yogurt, soft cheeses<\/td><\/tr>
Maltose<\/strong><\/td>Disaccharide<\/td>Glucose + glucose<\/td>~105<\/td>Malted grains, beer, malt syrup<\/td><\/tr>
HFCS-55<\/strong><\/td>Added sweetener<\/td>55% fructose + 45% glucose<\/td>~58<\/td>Soft drinks, sweetened drinks<\/td><\/tr>
Erythritol<\/strong><\/td>Sugar alcohol<\/td>4-carbon polyol<\/td>~0<\/td>Stevia blends, “zero-sugar” products<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

*Glycemic index (GI) compares how fast a food raises blood glucose against pure glucose (set at 100). Lower numbers mean a slower, smaller blood-sugar rise. Reported GI values are approximate and vary by test food, population, and method. HFCS GI varies in real food matrices; the chart value reflects its calculated glucose-fructose composition. Reference values from the international GI table (Foster-Powell K et al.,* Am J Clin Nutr* 2002, PMID 12081815<\/a>).<\/sub><\/em><\/p>\n\n\n\n

Monosaccharides \u2014 the building blocks<\/h2>\n\n\n\n

Monosaccharides are the simplest sugars. Every other sugar in your food eventually breaks down into one or two of these during digestion.<\/p>\n\n\n\n

Glucose<\/strong> is the form your body actually uses for energy. When a glucose meter or CGM reports your “blood sugar,” it is reading glucose specifically. Pure glucose is the reference standard for glycemic index (set at 100), so every other carb is rated against it. Glucose is the fastest-absorbing sugar \u2014 it enters your bloodstream within minutes of eating and drives an immediate insulin response.<\/p>\n\n\n\n

Fructose<\/strong> tastes the sweetest of the common sugars (roughly twice as sweet as glucose) and has a much lower glycemic index. The reason it does not spike blood sugar much \u2014 fructose is processed mostly by your liver and small intestine, not the bloodstream directly. That makes it less obvious on a CGM curve, but it does not make it metabolically free. With high or chronic intake, the liver converts excess fructose into fat through a process called de novo lipogenesis (Tappy L, L\u00ea KA, Physiol Rev<\/em> 2010, PMID 20086073<\/a>) \u2014 which over time can contribute to non-alcoholic fatty liver disease, raised triglycerides, and reduced insulin sensitivity.<\/p>\n\n\n\n

A 2018 study refined this picture \u2014 preclinical work showed that at moderate doses, the small intestine converts most dietary fructose into glucose and other organic acids before it reaches the liver. The liver only gets overwhelmed when fructose intake is high \u2014 like a large soft drink in one sitting (Jang C et al., Cell Metab<\/em> 2018, PMID 29414685<\/a>). So a piece of fruit is not the same as a 20-oz soda even though both contain fructose.<\/p>\n\n\n\n

Galactose<\/strong> is the third monosaccharide. It only appears in your food as part of lactose (the sugar in milk). On its own, galactose is rare \u2014 your body sees it almost entirely after digesting dairy.<\/p>\n\n\n\n

Disaccharides \u2014 the everyday sugars<\/h2>\n\n\n\n

Disaccharides are two monosaccharides chemically linked together. Your gut splits them apart within minutes of eating.<\/p>\n\n\n\n

Sucrose<\/strong> is table sugar. It is one glucose linked to one fructose, in equal parts. Whether it comes from sugar cane or sugar beet, the molecule is the same. After your gut enzymes split it, the glucose half raises blood sugar quickly, and the fructose half heads to the liver. For more on how sucrose behaves in your body, see Ultrahuman’s sucrose explainer<\/a>.<\/p>\n\n\n\n

Lactose<\/strong> is milk sugar \u2014 glucose linked to galactose. Most adults outside Northern European and some African populations make less lactase (the enzyme that splits it) over time, which is why lactose intolerance is common worldwide. Lactose has a lower glycemic index than sucrose (around 46) because it is split more slowly and one of its halves is galactose, which does not raise blood sugar much.<\/p>\n\n\n\n

Maltose<\/strong> is glucose linked to glucose. It is the main sugar in malted grains, beer, and malt syrup. Because both halves are glucose, maltose has the highest glycemic index of any common sugar (around 105) \u2014 it can spike blood glucose even faster than pure glucose itself.<\/p>\n\n\n\n

Invert sugar<\/strong> is sucrose that has been pre-split into separate glucose and fructose. It is used widely in soft drinks, candies, and baked goods because it is sweeter per gram than table sugar and resists crystallization. For a deeper walkthrough, see Ultrahuman’s invert sugar explainer<\/a>.<\/p>\n\n\n\n

High-fructose corn syrup (HFCS) \u2014 its own category<\/h2>\n\n\n\n

HFCS is corn syrup that has been processed to convert some of its glucose into fructose. Two main blends are used commercially:<\/p>\n\n\n\n