Resistant starch is one of the better-researched functional fibres available. It's also the clearest example in AlkaLean of a gap between a real ingredient and a research-level dose — so let's do the arithmetic properly.
Starch that resists digestion in the small intestine. Instead of being broken into glucose and absorbed, it reaches the colon intact and ferments — behaving much more like a fibre than a starch.
Potato starch, green bananas and cooked-then-cooled rice and potatoes are common dietary sources.
Fermentation of resistant starch produces butyrate particularly efficiently. Butyrate is the primary fuel for colonocytes — the cells lining your colon — and is involved in gut barrier integrity and immune signalling.
Human studies have examined effects on insulin sensitivity, post-meal glucose response and satiety signalling. The research is genuine and reasonably substantial.
Here's the part that matters. Studies showing metabolic effects from resistant starch typically use 15 to 30 grams per day. Some go higher.
AlkaLean lists 100 mg per capsule. That's 0.1 grams.
Not useless — but honestly framed, it's a contribution rather than an intervention. 100 mg of resistant starch will ferment and produce some butyrate. It will not replicate what a 20 g dose does in a trial, and no page should imply otherwise.
It's also worth noting that AlkaLean pairs it with 211 mg of inulin, bringing total prebiotic fibre to 311 mg. Still well under a gram — the average adult fibre recommendation is 25–38 grams daily from food.
Food. Cooked-and-cooled potatoes or rice, slightly green bananas, legumes, oats. A single serving of cooled potato salad can deliver several grams of resistant starch — ordersof magnitude more than a capsule.
That's not an argument against the supplement so much as context for what it's realistically doing alongside your diet rather than instead of it.
Credit where it's due: AlkaLean does publish 100 mg. A proprietary blend would have hidden it entirely, and plenty of competitors do exactly that. Being able to run this comparison is only possible because the label is transparent — which is a point in the product's favour even though the number itself is modest.
Read next: the other prebiotic in the formula, or the full dose section.