For some reason, it's extremely hard for me to break away from a certain body fat percentage and look despite dietary changes, changes in activity, etc. Switching to paleo, going low carb, zero carb, walking hours a day, not walking much, or trying a range of other tweaks in sleep and behaviors never seem to make a difference in my body composition.

Some days I eat 2 meals, some days more. I eat naturally, as in when I'm hungry, and eating what healthy paleo foods I crave. And yet I've actually been gaining weight to the point of returning to the same bodyfat percentage (but higher weight) as 18 months ago when I went low-fat and counted calories. I don't get it! I get so much more protein and way less fructose and sugars and grains. I lift weights. I thought these things were supposed to make me lean.

Anyway, to sum it up, my body has a preferred weight that I maintained for years before starting a diet and exercise lifestyle. After quitting a bout of lowfat calorie counting coupled with daily treadmill visits, the weight started creeping despite a healthier and more lean-condusive lifestyle adopted. I've gone through several different periods of lifestyles, and the weight never budges. I'm pretty sure my body is fighting to maintain homeostasis.

How do I lower my body's preferred set point?

Edit: Female, 19, 5'6 and currently 150 lbs.

Was about as chubby (@130-137 lbs though) from around 13-15, had no problem maintaining this. Before that I had been a fat kid (170+), who moved to a new country and just ended up naturally transforming (as in, my access to poptarts and hotpockets was suddenly taken away).

Eating patterns- Constantly varies. Predominantly low carb, but in the last month I have been trying to have one serving of starch a day. I barely ever repeat a meal. I eat a lot of coconut milk, ground beef, vegetables such as spinach (sauteed or creamed), sweet potato, cabbage and salads with bell peppers and onion. In the mornings I'll have cream in my coffees and some eggs if I'm hungry. Salmon and liver at least once a week.

Over the past 6 months exercise habits have been really varied. I had one point where I did an hour of lifting 2-3 times a week. Then I did lifting twice a week and was on my feet at work for 8 hours, walking around most of the time. Then I lost access to a gym and was walking often and doing bodyweight circuits 3x's a week. Then I came back and toned things down, doing just one intense lifting session followed by HIIT, and one HIIT only session a week. My body composition has not changed noticeably throughout all these different periods, apart from a little muscle gain in my triceps (still slowly worked my way up to original pre-diet body fat percentage though).