Are sugar alcohols a dieter’s best friend, or their worst enemy? Despite the name, sugar alcohols are neither sugar nor alcohol. They’re naturally present in small amounts in fruits and vegetables, but most of what we consume is produced industrially and added to diet products, protein bars, and “sugar-free” foods.
They’re often marketed as the perfect low-calorie substitute for sugar, but the reality is far more nuanced. Let’s break down what they are, how they affect your body, and whether they deserve a place in your nutrition plan.
What Are Sugar Alcohols?
Sugar alcohols are a class of carbohydrates used as sweeteners. Unlike artificial sweeteners such as sucralose or aspartame, they aren’t calorie-free. They typically provide 1.6–3 kcal per gram compared to sugar’s 4 kcal per gram, depending on how much is absorbed in the small intestine.
Common types include sorbitol, xylitol, maltitol, isomalt, lactitol, and mannito, each with varying sweetness levels and digestive effects.
The Hidden Catch: Calories and Labelling
One of the biggest misconceptions is that “sugar-free” automatically means calorie-free. Nutrition labels don’t always reflect the true energy content of products containing sugar alcohols.
For example, sugar-free maple syrup often lists “<1 g carbs per serve,” but a 35 ml serving may still contain 18+ calories. Apps like MyFitnessPal frequently underestimate these products, which can quietly add up in a dieting phase when precision matters.
Digestive Side Effects
The real catch comes from digestion. Sugar alcohols are poorly absorbed in the small intestine, meaning most pass through to the large intestine where bacteria ferment them. This process produces gas, bloating, and, in some cases, diarrhea.
Additionally, their osmotic effect pulls water into the bowel, further contributing to discomfort. This is why eating a few too many “sugar-free” protein bars, gums, or ice creams often results in stomach issues.
Performance and Physique Implications
Beyond digestion, sugar alcohols can affect athletes and physique competitors in other ways.
Bloating & Water Retention: Can mask leanness on the scale or in the mirror.
Food Focus: Sweetened products can heighten cravings during contest prep.
Headspace: Gastrointestinal distress adds unnecessary discomfort in already challenging phases.
That said, there are some positives. Xylitol, for example, may help protect against dental cavities, making it a useful alternative in gum and mints.
The Bottom Line
Sugar alcohols aren’t inherently harmful, but they’re not a free pass either. Moderate use is generally safe, but large amounts can backfire, physically, mentally, and in terms of performance.
For most people, the best strategy is balance. Recognise sugar alcohols as a tool, not a solution, and remember that whole-food carbohydrate sources like oats, rice, potatoes, and fruit are usually superior for fuelling training and recovery.
Are you struggling with diet strategies that leave you bloated, low-energy, or second-guessing your food choices? At The Bodybuilding Dietitians, our 1:1 coaching provides evidence-based nutrition support tailored to your goals, whether it’s fat loss, performance, or stage prep. Reach out below!