Intermittent fasting?

Hi there! If that profile picture is you, then I don't think you need to lose any more weight! :bigsmile:

Intermittent fasting helps to burn fat through very simple biochemical principles. On the lean gains program, I believe you typically fast for 15 hours, have some BCAAs then do a one hour workout, and then have your first meal of the day, which should provide all the nutrition for your post-workout recovery. You can then eat the rest of your remaining calories whenever you like during your 8 hour eating window. This type of IF is usually referred to as a condensed eating window because you actually eat every day.

Your body constantly monitors blood glucose levels to ensure they are adequate to feed your brain. This is because your brain's primary source of energy is glucose. When glucose is abundant, your liver and muscles will store it as glycogen. Any remaining glucose will then be stored as fat. When you fast, the first thing your body does is begin to use up its glycogen stores in muscle and liver; this keeps your blood glucose levels stable, and fuels your brain. When your glycogen runs out, your body must produce its own glucose in order to continue fueling your brain. It does this by starting out with some precursor molecules (can be lactic acid or amino acids) and your liver performs gluconeogensis, which is the process of making glucose. This biochemical pathway requires energy, and that energy comes from the oxidation of fatty acids.

So, on the lean gains program, you fast for 15 hours, which is sufficient to work your way through your glycogen stores and get you into fat-oxidation mode, and then you supplement with branched-chain amino acids (BCAAs), which provides your body with the precursor molecules, then you workout, which causes your body to burn more fat to make more glucose (because you've only given it protein, no carbohydrates), and then when you're done working out, you break the fast and consume all the nutrients necessary to maintain your lean muscle mass. Incidentally, when you work out, you also produce lactic acid in your muscles which is recycled into glucose via the cori cycle, another fat-burner.

Other variations of IF are effective for fat loss as well. And as long as you eat enough protein to meet your nutritional needs when you are not fasting, you really shouldn't experience much in the way of lean mass loss while fasting.

Also of note, IF has been shown repeatedly to have positive long-term effects on overall health and lifespan extension. This is thought to be the result of a process called hormesis. Basically, denying your body of food for short periods of time places mild stress on your cells. This stress in turn causes your cells to initiate a number of protective mechanisms that help to increase their resistance to stress. Over time, periodically stressed cells become more robust and healthier. The concept is similar in some ways to weight lifting: you lift weights, which places stress on your muscles. Your muscles respond by becoming stronger, such that they can eventually tolerate more stress (lift more weight).

Some people may object to IF on the grounds of driving your body into "starvation mode". The truth is that starvation mode does not occur from one day of not eating. Period. It's a gradual change in your body that takes place over sustained periods of severely restricted caloric intake. If you were to drop your daily calories to 500 per day, and sustain that level for long periods of time, you would definitely see a reduction in BMR that could not be accounted for solely by changes in body composition. But that is not what you are doing with IF. You may choose to abstain from food entirely for 1-2 times per week and eat normally the other 5-6 days, or you may choose to consume all of your calories during a shorter period of time each day. Both methods increase the amount of time your body spends doing gluconeogensis and thus increase the amount of time you spend burning fat, but do not inexplicably decrease your BMR, as long as you are eating properly when not fasting.

I'd like to try this. So do most people start on the 16 hour fast? When I'm fasting can I have coffee/tea? or should I avoid everything except water all together? Any other tips would be greatly apprectiated

Some people dive right in on longer fasts. I started with 14 hours fasts and after a week switched to 16 cause it worked better with my schedule and I wasn't having any problems at 14. Now I occasionally throw in a 20-24 hour fast - especially on Mondays after a calorie heavy weekend. Usually I can tell when my body needs one.

I just do water but I don't like coffee or tea. I sometimes drink diet pop (very rare). As long as their aren't any calories (or very minimal) coffee/tea should be fine.

I do IF but not the Leangains version. I do two 24-hour fasts per week (Tuesdays and Thursdays). Basically, I stop eating after dinner on Monday night and don't eat again until dinner on Tuesday night, then the same thing Wednesday night to Thursday night.

It took some getting used to, but it's not that difficult for me anymore. I read Eat. Stop. Eat. and am following those principles in terms of what you can and can't have while fasting. I can drink black coffee, tea, water, and diet soda, and I can chew sugar-free gum.

I've only been doing it for about a month, so I can't really speak about results so far. I can say it is nice not to have to worry about food for two days out of the week. I have lost inches and have more energy, but I am also doing a really intense kettlebell training program for fat loss and following a heavy protein/low carb diet at the moment, so it's probably a combination of all of the above for me.

ETA: I did some research on the effects of fasting on training days for people who do strength training, and there is some evidence to suggest that muscle damage occurs in people who fast immediately prior to strength workouts. Thus, I do not fast on training days.

Awesome, thank you!! I think I'm gonna try it starting tonight.

I'll agree with jq2122 - If I eat closer to paleo I'm way less hungry then when I don't. Last night I had salmon and a baked potato - no stomach growls this morning. Tonight I'm having pizza - I know I might have to deal with my stomach a bit tomorrow. I just think it's worth it for the pizza on occasion.

When I was first starting my stomach growled occasionally at normal meal times. It wasn't that I was actually hungry just that my stomach was trained to expect food then.

Do you still workout during the 24 hour fast?

Oh okay. I'm a little concerned about working out and feeling faint from not eating. But I'll try and see how it works. I fasted this week for about 2 days but I was a little apprehensive to exercise.

I made it 14 hours!! I guess it's not too bad for my first day!

yeah I was hoping to jump right into a 16 hour but I think I will keep going at 14 for a little while and go from there. Can anybody tell me about the results they've seen by doing this? I'm about 12-15lbs from my goal weight and I'm hoping this will help.

Wow thats great. What kind of schedule are you on? do you fast daily or a few times a week?

I didn't do so great over the weekend....I went over my feeding time by a little bit and I ate pretty bad. Today is a new day! The last thing I ate was 10:30 last night so I'm trying to make it to 2:30 for 16 hours. I find its so much easier during the week when I'm at work then on the weekends when I'm out with friends and family.

You are so right. It's easy waiting till 1 pm but not eating late at night when you're around people that are eating bad is so difficult!! Well I just made it 12 hours and I'm pretty hungry. I hope I can make it the 16 but it might be another 14 day for me.

I've never been big into pop other then the occasional diet coke but I can just imagine how much better you feel switching it for water. I try and get 2-3 liters of water during the work day and then a glass or 2 at night but lately it's been hard to keep up with it.