Has there been research done on this?
To explain, just in case - lets say my TDEE is 3000 kcal per day. If I practice IF, but still consume 3000 kcal per day, will there be any measurable health benefits (compared to just eating the same 3000 kcal normally)?
Disclaimer: I am not a healthcare professional or a nutritionist.
I read Dr Fung’s Obesity Code, and as he explains it, constantly elevated insulin levels in our body inhibits a process called “lipolysis”: which is the process of extracting fat molecules (fatty acids) from your fat cells for producing energy. When this lipolysis process is inhibited by the presence of insulin due to eating for a long duration of time in a day (say from 7:00 AM to 10:00 PM with constant meals+snacks), fewer fatty acids are available from your fat cells to fuel your muscles and tissues all day long. In simple, layman terms, insulin spikes equates to turning OFF your body’s ability to burn fat molecules for fuel. On the contrary, if you restrict eating to only 4 hours, as an example, the body does not produce any insulin spikes for the vast majority of the day, any Insulin Resistance is corrected and the body gets the chance to burn stored fat using lipolysis.
I highly recommend reading Dr Fung’s books and listening to his talks on youtube (in the book, he points to some research and scientific sources if you are interested in digging into it). Reading his books taught me why for 15 years CICO and exercise did not work for me and why I always had “stubborn fat” that would not budge. I think that he explains these contexts far better than I could ever do! Obviously, it goes without saying, don’t eat all your calories in desserts or junk food when you do IF! In my case, I eat the same as before (which was already healthy with whole foods, vegetables, no processed foods etc) but just restrict the eating window drastically.
My experience is no. If you eat the same amount of calories but you just do it at dinner time you won’t lose any weight. But the thing is that if you do IF it will cut out all the snacking you do during the day so it makes you eat fewer calories and that’s where the weight loss comes from.
Read Obesity Code and Delay, Don’t Deny. If you are giving your body a designated (most beneficial is 18 hrs-20 hrs) time of not releasing insulin (clean fasting) then YES. IF is not intended for calorie counting. There are many days I eat over my normal calories (I tracked a few of those days out of curiosity) and I lost weight. The focus is not calories, but rather not releasing insulin. This is when our bodies use our fat for energy.
With that said, overtime, IF has a benefit known as appetite correction. Our bodies learn to crave nutritional foods and we learn to listen to our bodies and stop eating when full. This takes time, as our metabolism is healing.
Not all calories are created equally. So if you are eating 3000+ calories in garbage processed foods and sugar, you’re kind of defeating the purpose of IF.
The idea of IF, as I understand it and from my own personal experience with it, is that it helps with eating right too. Eating less processed food, less unrefined carbs, eating more veggies/fibrous foods should be what you break your fast with.
Most people are overweight (barring any other physical reason) because they mindlessly eat. IF means you become mindful of eating again.
TL;DR: eating 3000+ calories of veggies, lean meat, nuts/seeds, and fruits is really hard to do. With IF you naturally eat less because you don’t eat as often and you are more mindful about what you eat (you snack less…if you’re doing it right).
Yup. The benefits of fasting are touched with IF/OMAD…PF dips the toe deeper into the water….but you still get them
Struggles:Intense desire to sleep due to huge meal lol
Bigger insulin spike…meaning you will store fat a bit easier for a period. This might equate to wanting to eat say 2900 of the 3k or something if you have >20% fat in the food
To answer your question plainly: Yes there has been research done on this.
If you go to https://pubmed.ncbi.nlm.nih.gov/ you can look up Intermittent fasting as a therapy and you will see many articles and from there I am sure you can locate the peer reviewed literature you are looking for. IF and diabetes management is a pretty well researched area for starters.
Circadian Code - Dr. Satchin Panda -This person has done a ton of research around daily rhythms and how the body is affected.
I hope you find what you are looking for and I hope you are successful meeting your goals.
If you truly incorporate IF into your lifestyle AND you don’t go crazy in your eating window the calorie deficit comes along for the ride :).
If you are counting calories you will not be successful long term. For proof see every diet’s long term success since the 80s. It’s non existent.
Good luck!