05/18/2026
Your “net carbs” math is lying to you — and here’s the science a lot of coaches skip.
Fiber isn’t digested in your small intestine. It’s fermented by your gut bacteria in your colon into short-chain fatty acids, which your body absorbs and uses as energy. That’s roughly ~2 calories per gram of fermentable fiber.
But here’s the part no one talks about: that number is an average. Your microbiome is unique. Some people’s gut bacteria ferment fiber more efficiently than others, meaning they extract more calories from the exact same meal. Two people eating identical 1,800-calorie days can be absorbing meaningfully different amounts.
So when you subtract every gram of fiber from your carb total — you’re not eating “free” calories. You’re eating a moving target. Same with sugar alcohols. Although they’re very low calorie, they’re not calorie-free.
For body recomp: track total carbs. Let fiber be a bonus for satiety, digestion, and metabolic health — not a reason to under-count.
Save this. Your future leaner self will thank you 😊