Nope, you can increase insulin snesitivity eating 10 times per day. Ypu just have to eat the right foods. You will burn fat no matter how many times you eat if you are in a caloric deficit. Honestly. I probably fast 12 hours a day without even thinking about it, it is just my personal eating schedule. Eating when you are hungry makes you more aware of what could possibly be going on in your body, say someone gets hungry an hour after eating a high carb meal, this is a sign they are insulin resistance because they cannot assimilate much of the glucose in their tissues so their cortisol sky rockets to release fatty acids to fuel cells and they are left with high blood sugar and high free fatty acid content in the blood. It makes more sense to focus on what, how, and why you are consuming foods rather than when because a restricted eating window limits the amount of macro as well as micronutrients you can eat. I have tried IF and there were many problems such as a low temoerature, bad sleep, unnatural hunger cues throughout the day. IF does not change what really matters, your diet, it only constitutes when you can eat (poptarts and cookies).