*edit* - thank you all for the explanations - it helped me understand it so much better.
I completing understand the concept of being able to calorie restrict but can someone explain to me how a 16/8 works for weight loss like I am a five year old. I hear these crazy claims like lose 1/2 pound a day. I am just trying to get the gist.
I naturally do a 14/10 so I decided this week to switch to 16/8 without an issue. I do calorie restrict - 1250 with 30 minutes of cardio a day. I had a bunch of babies in the last couple of years so I am trying to get off pesky extra baby weight .
All food causes an insulin response—carbs cause a bigger insulin response than protein or fats. By limiting your meals to a certain window, you give your body a break from having to produce insulin to control blood sugar. Since insulin is the hormone responsible for fat storage, lower insulin allows your body to tap into fat stores for energy.
It’s not just calorie reduction. You’re turning off a metabolic function that makes it hard to lose weight for hours at a time.
Your body will use it’s stored fat and glycogen for energy after it has exhausted the eaten stuff. There have been endurance cyclists who have gone for miles without eating and their blood glucose remains at a stable level. Your body will use itself for energy if there isn’t anything fresh available.
For each full-day fast (~36 hours at a time), you would lose approximately 1/2 lb of fat per week. So if you do three 36 hour fasts a week (ADF), you’d lose about 1.5 lbs due to fat burning per week — potentially more if you are also in a calorie deficit on your eating days.
So I am guessing that you are hearing about the “1/2 lb per full day fast” data and confusing it with what you are hearing about 16-22 hour daily routines. Typical results for 16:8 are 0-2 lbs per week, depending on how strict you are with your intake during your eating window.
The main idea is that people on standard western diets, characterized by processed carbohydrate overabundance and 24/7 consumption, tend to be sugar-overloaded a.k.a. insulin-resistant, which is the precursor to the modern lifestyle disease of metabolic syndrome / type 2 diabetes. Insulin-resistant individuals are thought to expend less energy than expected given their stats and activity, for one because of permanently elevated baseline insulin driving intake calories toward storage and holding back the release of stored fat, and for two because of insulin receptor down-regulation – cells essentially defending themselves because they can’t metabolize any more sugar. Thus it is not necessarily that fasting magically increases expenditure but rather that it helps restore normally expected expenditure, by giving the pancreas a chance to rest, circulating insulin the chance to fall, fat stores to be mobilized, and over time insulin receptors to up-regulate anew.
When you fast, insulin goes down… your body becomes catabolic and burns stored fat.
You will lose fat after your fast.
Now. If you decide to overeat like crazy after your fast, you will just gain back the fat.
BUT. Fasting consistently over a period of time will probably reduce your basal insulin levels and your hunger won’t be constant and ravenous like how it is when you are hyperinsulinemic… and therefore, you eat less to get full compared to before.
And hence, you lose weight :)
Being in a calorie deficit isn’t restricted to a 24hr window, we don’t actually know the specific times for fat loss during a calorie deficit.
Imagine that you’re doing a calorie deficit for most of the day, your body is burning fat, and when your window arrives you enter a surplus to re-invigorate/sustain.
So think of it has being in a functional “mini” calorie-deficit, with a small window for a surplus