Separating what is marketing and fashion from what the evidence actually says
In short
Maltodextrin does not cause digestive problems on its own. Discomfort comes mainly from two things: using it as a single carbohydrate source at high doses, and not drinking enough fluid with it. Combined with fructose in the right ratio, several studies in trained cyclists and runners find no differences in digestive comfort even at 90-120 g/h.
- It is not a synthetic laboratory compound. It is produced by partial hydrolysis of corn, potato or rice starch: it is starch broken into shorter chains of glucose.
- Its high glycaemic index is an advantage during exercise, not a risk. What is a problem at rest is exactly the property you want when the muscle is consuming that glucose in real time.
- The "rollercoaster effect" is real, but it is not the ingredient's fault. It appears when you exceed the limit of a single transporter, roughly 1 to 1.2 g of carbohydrate per minute. It is fixed by combining maltodextrin with fructose, which uses a different route.
- There is a real scientific debate, and it is not a hoax. It concerns chronic, high consumption within a Western diet, in animal models and in people with a genetic predisposition — not the occasional use of a gel before or during effort.
- That is why at Novafit we do not rely on a single source: spreading the load across several reduces exposure to any one of them and improves absorption.
Introduction
Maltodextrin has become one of the most singled-out ingredients on social media in the world of sport. It gets blamed for everything: that it "spikes" blood sugar, that it "wrecks" your stomach, that it is "a dangerous industrial product". Part of that distrust comes from beliefs repeated without checking, amplified by trends and, at times, by the commercial interest of brands selling alternatives. But being rigorous also means not falling into the opposite extreme: there are a couple of points where science still has open questions, and they deserve to be told with the same honesty. Let us go point by point.
Myth 1: "It is a dangerous industrial additive"
What the evidence says: maltodextrin is obtained by partial hydrolysis of starch (usually corn, potato or rice). It is not a synthetic laboratory compound: it is the result of breaking starch chains into shorter pieces of glucose. It is classified as safe both by the FDA, (GRAS category, "generally recognised as safe"), and by EFSA in Europe, and it has decades of documented use in clinical and sports nutrition.
The real nuance: "safe" does not mean "without any biological effect" — no substance is. Like any ingredient, its suitability depends on the dose, the frequency and the context of consumption, not on whether it sounds "industrial" or not.
Myth 2: "It has a very high glycaemic index, so it is bad for the body"
What the evidence says: it is true that its glycaemic index is high (85-105), even higher than that of table sugar. But this figure has to be read in context. A high glycaemic index is a problem when we are talking about a person at rest, seeking metabolic stability throughout the day. During endurance exercise it is exactly the property you are looking for: a source of energy that reaches the muscle demanding it at that precise moment.
The underlying error: transferring a metabolic-health recommendation made at rest (avoiding glucose spikes) directly to a context of active exercise, where the muscle is consuming that glucose in real time rather than storing it, are two different physiological situations and cannot be judged by the same rule.
Myth 3: "It causes energy highs and then crashes, (the rollercoaster effect)"
What the evidence says: this effect is real, but it is not an inherent property of maltodextrin; it appears when it is used as a single source of carbohydrate at high doses. The gut has an absorption limit for one single type of glucose transporter, (SGLT1), of roughly 1 to 1.2 g of carbohydrate per minute. Past that limit with a single source, the body cannot absorb it all efficiently.
The solution science confirms: combine maltodextrin with fructose, which is absorbed by a different route, (the GLUT5 transporter). Using two routes in parallel increases the total amount of carbohydrate the body can use and avoids those energy swings. This is known as "multiple transportable" carbohydrates and is one of the best-replicated findings in exercise physiology of the last two decades.
Myth 4: "It always causes digestive problems"
What the evidence says: the digestive discomfort associated with maltodextrin in sport appears mainly for two reasons: excessive doses from a single source, (the same problem as the previous point), and insufficient hydration when taking it. When it is combined with fructose in the right ratio and taken with enough fluid, several studies in trained cyclists and runners find no relevant differences in digestive comfort compared with other formulas, even at doses of 90-120 g/h.
The real nuance: people with particular digestive sensitivity, (for example, those who already tolerate FODMAPs poorly), may notice discomfort at lower doses than average. This is true for maltodextrin and also for practically any fermentable carbohydrate; it is not a feature unique to this ingredient.
What is a real scientific debate, (and not a hoax)
To be completely honest: there are studies, mostly in animal models, investigating whether chronic and high consumption of maltodextrin as part of a Western diet could alter the intestinal mucus barrier and encourage inflammatory processes in people with a genetic predisposition to inflammatory bowel disease, (Crohn's, ulcerative colitis). It is a serious line of research, published in journals such as Frontiers in Immunology, and it should not be dismissed simply because it does not fit the argument that suits us.
That said, this finding has to be placed in its proper context: these are studies mostly in mice, on daily and sustained exposure over time, within the general diet, (think of ultra-processed foods that carry it as a constant additive), and in populations with a specific genetic predisposition. It is a very different context from that of a healthy athlete taking a gel or a bar occasionally, before or during effort. The evidence in human athletes, in that context of occasional use, does not show those effects. Even so, it is the reason why at Novafit we do not depend on a single carbohydrate source: spreading the load across several sources reduces exposure to any one of them individually, as well as improving absorption.
Myth and reality, in one table
| Myth | Reality |
|---|---|
| "It is a dangerous industrial product" | It is a starch-derived carbohydrate, with decades of documented safe use |
| "A high glycaemic index is bad" | It is an advantage during active exercise, not a metabolic risk in that context |
| "It causes energy highs and crashes" | Only if used as a single source at high doses; corrected by combining it with fructose |
| "It always causes digestive problems" | The problem is the dose and the single source, not the ingredient itself |
| "There is no scientific debate" | There is, but about chronic consumption in Western diets, not about occasional use in sport |
The Novafit approach
That is why our gels and bars combine several carbohydrate sources, (among them maltodextrin, fructose and Palatinose), instead of depending on just one, together with 30% real fruit pulp. It is not a response to a trend: it is the practical application of what the evidence has been confirming for more than a decade about how to maximise available energy and minimise digestive discomfort during effort.
Frequently asked questions
Does maltodextrin upset your stomach?
Not on its own. Discomfort appears mainly when it is used as a single carbohydrate source at high doses and when it is taken with little fluid. Combined with fructose in the right ratio and with enough hydration, several studies in trained cyclists and runners find no relevant differences in digestive comfort compared with other formulas, even at doses of 90-120 g/h.
Is maltodextrin a dangerous industrial product?
No. It is obtained by partial hydrolysis of corn, potato or rice starch, that is, by breaking starch chains into shorter pieces of glucose. It is not a synthetic laboratory compound and it has decades of documented use in clinical and sports nutrition.
Does it matter that it has a high glycaemic index?
It depends on the context. A high glycaemic index is a problem for someone at rest looking for metabolic stability through the day. During endurance exercise it is the opposite: it is the property you want, because the muscle is consuming that glucose in real time rather than storing it.
Why does maltodextrin cause highs and crashes?
That effect appears when you exceed the absorption limit of a single glucose transporter, SGLT1, which sits at around 1 to 1.2 g of carbohydrate per minute. Past that limit with a single source, the body does not absorb it all efficiently. The solution science confirms is not to remove it, but to combine it with fructose, which is absorbed by the GLUT5 transporter.
What are "multiple transportable" carbohydrates?
They are the combination of two carbohydrates absorbed by different routes, typically maltodextrin or glucose alongside fructose. Using both routes in parallel increases the total amount of carbohydrate the body can use and avoids energy swings. It is one of the best-replicated findings in exercise physiology of the last two decades.
What if I have a sensitive stomach or do not tolerate FODMAPs well?
People with particular digestive sensitivity may notice discomfort at lower doses than average. It is worth raising the hourly amount gradually and always taking it with enough fluid. This is true for maltodextrin and also for practically any fermentable carbohydrate: it is not a feature unique to this ingredient.
Should I worry about the studies on the intestinal barrier?
It is a serious line of research and should not be dismissed. But it needs placing in context: these are studies mostly in mice, on daily and sustained exposure over time within the general diet, and in populations with a specific genetic predisposition to inflammatory bowel disease. The evidence in human athletes, in the context of occasional use of a gel or a bar, does not show those effects.
References
- Jeukendrup, A. E. & Currell, K. (2008). Superior endurance performance with ingestion of multiple transportable carbohydrates. Medicine & Science in Sports & Exercise, 40(2), 275-281.
- Podlogar, T., Bokal, Š., Cirnski, S. & Wallis, G. A. (2022). Increased exogenous but unaltered endogenous carbohydrate oxidation with combined fructose-maltodextrin ingested at 120 g/h vs 90 g/h. European Journal of Applied Physiology.
- Zangara, M. T. et al. (2022). Maltodextrin Consumption Impairs the Intestinal Mucus Barrier and Accelerates Colitis Through Direct Actions on the Epithelium. Frontiers in Immunology.
- Systematic review of placebo-controlled clinical trials on maltodextrin effects on gut physiology. European Journal of Nutrition (2023).
- FDA, "Generally Recognized as Safe" (GRAS) status of maltodextrin.
- EFSA, safety assessment of starch-derived food additives.
Article produced by the Novafit technical team.
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