Hitting a weight loss plateau can be tough. Feeling like you're doing everything right and still not seeing your body change is frustrating - especially if you'd been previously losing weight.

But don't fear, there are reasons for it - not least that your body doesn't really want you to lose weight. When you cut back on calories, sometimes your body's response is to retain weight in order to protect against what it may perceive as 'deprivation'.

"Your body will then make you feel hungry because it thinks something is wrong and wants you to gain that weight back," says Peter LePort, MD, a bariatric surgeon and medical director of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in Fountain Valley, California.

Also, when you start losing weight (muscle or fat), your body's metabolic rate slows down, which means your body starts burning calories at a lower rate, too.

Frustratingly enough, there is also a 'set point' at which your body does not want to lose any more weight, says Fatima Cody Stanford, MD, an instructor of medicine and paediatrics at Harvard Medical School and obesity medicine physician at Massachusetts General Hospital. "You might notice that, no matter what you try, you are always within five to ten pounds of a baseline weight," she says. "When you attempt to lose weight, the body aims to defend its set point, via the brain, to keep you in a certain range."