Recently, and by recently I mean for about a month and a half, I've been attempting to practice intermittent fasting. To explain why, I'd have to back up a bit.
About five months ago, while training Brazilian Jiu-jitsu, I partially tore my right anterior meniscus; the inside portion of a figure 8 shaped ligament in between the knee joint. An MRI also revealed that I had cartilage erosion on the inside back of my right knee cap. The long and short of it is that it hurt like hell. I could barely walk for weeks, limped out of bed every morning, and couldn't train BJJ or do any kind of cardio for over three months.
I decided that I'd take the opportunity to switch from HIIT style training to heavy weights. Although I couldn't run, or even walk quickly, I could squat and deadlift, albiet slowly, since they don't involve lateral motion, and do upper body lifts a plenty. So, that's what I did. To make all this moving of heavy metal effective, I ate like food was going out of business - still paleo, but in roughly double the amounts I'd usually take in. Specifically, I upped my carb and fat intake big time. Two to three sweet potatoes a day, full fat cream in my coffee, dark chocolate along with protein shakes post work-out. The results were, I got bigger. I went from 61kg to 74.5kg during those three and a half months. Most of it was muscle. Sadly, some of it was fat.
Which brings me to intermittent fasting, or IF as it's known by those in the know. Thanks to posts on various paleo blogs, as well as the influence of the Hodge Twins, I thought I'd try intermittent fasting myself. If you don't know what that is, it's just fitting your meals into a shorter time frame. I chose the largest eating window, an 8/16 split, eating regular meals from 12:00-8:00 pm and fasting the rest of the 16 hours. Tighter splits such as 6/18, 4/20 and full 24 (done perhaps twice a week) are also common. I matched this with a whole 30, but to be honest, I cheated with coffee and some dark chocolate pretty often. As I said in the first paragraph, I'm terrible.
Proponents claim it allows greater usage of body fat for energy, release of testosterone and HGH, improved metabolism of blood sugar, and generally much more efficient fat loss matched with greater maintenance of muscle tissue than would be possible under a traditional 6-8 small meals a day, calorie restriction plus cardio fat loss approach.
I've tried the old calories in/calories out way of losing fat, and always felt drained, lost strength and felt sort of strung out, especially after workouts. Don't get me wrong, cutting calories works. But, it sucks. With IF, I've lost 10kg, while increasing in strength, hitting several PBs on deadlifts, squats and bench, and maintained or increased slightly on everything else. My abs, which had sadly disappeared during my bulking phase, have started to come back, and I feel less lethargic than when I was eating from morning to night to get the recommended grams of protein in.
If you'd like to try it, be aware that IF is not entirely pain free. It takes about 3 weeks to adjust, and I was starving at the tail end of my fasting period every day. Your body is used to getting food at certain times, whether it needs it or not, so be prepared for some gurgling stomach and heartburn. Have some almond butter or similar fat and protein rich food handy, and have a small spoonful if you're really going...nuts. Drink twice as much water as you normally would, and take some green tea or coffee to get yourself going in the morning.
Overall, I'd say IF works for fat loss, especially that stubborn fat us mid/late 30's guys start to build up around the mid-section that just won't take the hint and get lost, no matter how much you stare at it in the mirror while glaring angrily and stamping your foot.