So I wanted to start IF, and now I am not sure anymore, because of the following: Is it true that I have to go low carb? I actually thought it’s about not eating too much calories, but I heard somewhere that if you eat carbs after the fasting period you could actually gain weight especially if combined with fats. If I have to eat low carb, low fat and fast, I don’t think I want to do IF. I became interested in IF because I got told this is not like a diet. But cutting carbs, is just that. Also: if suppose I stop with IF when I lost enough weight, will I gain weight again when I eat just normally (e.g. 2000 kcal a day)?
Intermittent fasting is just that: fasting. Plenty of people have had success with IF without going low carb or low fat or sometimes without changing their diet at all. Going keto or low fat can potentially speed up results since you’ll be in ketosis constantly, but it isn’t required. The only way you’ll gain weight is if you are overeating or eating too many calories during your eating window.
As for maintaining, IF is just a tool for losing and maintaining weight. So IF or not, if you’re eating at maintenance, you’ll maintain your weight. However a lot of people adapt IF as a lifestyle and find it easier to maintain with it. Also I feel like I should mention that if you’re treating this as a diet, or a phase to be done with once you reach your goal, maintaining is harder when you go back to your ‘normal’ eating habits.
Do IF however you want, OP. If you are happy with your results, awesome. If not, tweak your approach. You mentioned 2 other ways of eating that people sometimes layer in with IF, it’s not required. You might want to check out some basic fasting vids on Dr. Jason Fung’s YT channel to get started, he will answer a lot of these questions. It can be optimal to eat more whole foods and less processed foods for health and weight loss, but IF can work with many eating approaches. Good luck!
If I remember correctly, going low carb as part of IF is more about ensuring you’re not crazily impacting your blood sugar with too many carbs/sugars, which can make it more difficult to fast (cravings). That said, IF does not require a low-carb diet or keto. Personally, my macro distribution is pretty balanced, and my carbs tend to also come from whole grains/vegetables.
Edit to add: re the weight question, the energy stored in fat must come from an input (such as eating), so it would be an increase in calories above your TDEE that causes weight gain. Going off IF would not make you gain weight unless it means you are also eating more.
Low carb diet will accelerate the process but IF by itself will cause you to lose weight.
Think of IF like a jet engine. The plane flies just fine. Adding low carb diet and exercise is like adding an afterburner.