Weight / Fat loss

Could you explain how this works please. I would genuinely like to know how this works. We are a machine and if energy in = C_1, i.e calories in and energy out = C_2, i.e output / exercise if you don't alter one of these such that C_2 > C_1 how will you loose weight? I understand that diffrent foods will cause sugar spikes, craving e.t.c but if your weight is stable then C_1 = C_2. You can change fat into muscle but I always thought muscle weighs more than fat.

It is not just 1+1=2, it's how the body processes food and when it slows down in processing food. But you acted as though losing a stone or two in several months was batshit crazy and I'm saying that it's not. 2x4=8x3=24. 2 lbs per week weight loss is healthy and sustainable. Anything over that done for longer than about one month without a serious plan dealt with by a doctor and/or nutritionist is bordering on fad diet that probably won't stick around long term.

But for instance, I ride my bike at least 15 miles, up two hills each way, at least 5 days per week, yet I don't have flat abs b/c a) I'm genetically predisposed to this (I've always had a little belly, even if before it didn't stick out this much), and b) I eat too many carbs at the wrong times, including alcohol. It ain't rocket science.