I ran into this problem my senior year and ended up going down to 1100 calories and working out 2 hours a day and not losing any more body fat. In fact the only thing I was losing was muscle in my legs and back because they were the two muscle groups I never lifted weight with at the time. By losing this muscle it only decreased my metabolic activity and made me burn less calories naturally. However the fact that I was burning less calories than normal was not the reason why I was not losing fat anymore.
At that point in my diet I had been under 2000 calories a day for months and my body was in starvation mode. There is a hormone in the body called leptin which is the king of body fat metabolizing hormones. This is the strongest hormone in the body that tells it to burn it for energy. But because I was eating so little my leptin levels were drastically low. The only way to increase your leptin levels is to actually eat MORE. When I say eat more I mean go out and for one day eat pancakes, pizza, burgers, cake, anything you want.
By doing this ( eating way over your maintenance level) your body thinks it is done being starved and will continue to burn fat for energy. As soon as I started eating more, my weight began to drop - it didn’t make sense to me at the time because I was eating 1000 more calories than I used to but my bf was going down!
Most people will not have to worry too much about starvation mode until they get down to sub 12% bf ( in my opinion ) or have been dieting for months and always eating at a caloric deficit. However I do advise anyone who is dieting that if they are eating 500 less calories a day than they are burning or losing 1-3 lbs a week they should eat about 500 calories over their maintenance level 1-2 times every 2 weeks ( depending on how lethargic you feel). This will restore leptin levels and cause you to continue burning fat at an amazing rate.
Tony isn't a licensed nutritionist yet, so he can't give anyone advice on what to do. Please consult your doctor for his professional opinion on a diet/nutrition program that will work for you.
Tony's blog is a journal of his experiences and what has worked for him. He lists general guidelines and suggestions only. He is NOT a professional.