I've never got this carb sensitivity stuff?
Consider the logic. Suppose your on a 500 cal deficit. You consume carbs, this jacks your insulin, you store the carbs as fat (on assumption of extreme carb sensitivity: metabolic syndrome etc).
2 possibilities:
(1) you have no stored glycogen - because you store all carbs as fat - so you burn fat as your body doesn't have carbs to use. Either way you still burn fat, and on a 500 cal deficit, you still lose fat. Let's say pound per week (if u only lose fat).
(2) you have no stored glycogen - because you store all carbs as fat - but your insulin is so jacked you can't oxidise fat. Your body only uses muscle cells for energy.
But your in a calorie deficit. So all the calorie deficit is fueled by muscle protein as your elevated insulin prevents fat oxidation. But a pound of muscle is only 600 calories (mainly water; muscle is 4 cals per g: see 3500 Calories: A Pound of Fat or Six Pounds Of Muscle?), so you lose 3500/600=5.8lbs of muscle per week.
The second scenario strikes me as VERY unlikely.
believe me, ive been dieting since 1999 and have tried everything. i have to eat very low calorie and very low carb to make body fat loses. ive maintained over 200 pounds with under 12% bf on less than 2300 calories a day and im 5'5". everyone is different, ive figured my body out. its just the way i am. i know a close friend who is going for his pro card who eats 200 grams of protein a day, 250 grams of carbs a day, and 50 grams of fat. hes 5'6", 190, 6% bf- everyone is different. in his opinion, show him someone who needs 3500 calories a day to maintain their bodyweight and he says they must have a hole in their stomach.
also, in place of the carbs im taking in upwards of 120 grams of fats a day. look up dave palumbos diet schemes. they work for nearly everyone who uses them, including dave who is 260 and like 4% bf. my body is not chewing up muscle by 6 pounds a week. that whole scenario is in a vacuum and fortunately for us, life doesnt happen in a pitri dish in a lab.