Losing Weight without Exercise

I lost my first hundred pounds without doing a single exercise - I stopped eating enough food for three people and just ate a whole lot less. I didn't know about MFP back then.

If you've used MFP's food or exercise tracker for any decent amount of time, you will likely have realized by now that it's incredibly easy to out-eat all of the calories you burn through exercise in a day. The point I'm trying to make is that your diet is the central foundation for determining your weight. You can't out-run a bad diet.

Losing weight is simple: take in less calories than you expend. It's a basic law of physics (google "conservation of energy" or "laws of thermodynamics"). Of course, just because it is simple doesn't mean it's easy, and millions of people have come up with all sorts of scientifically unsound tricks and gimmicks and products and diets that promise you weight loss while magically sidestepping this basic law of energy.

Try to eat roughly the same number of calories for three weeks and measure your weight before and after.
If you went up, reduce your calorie target.
If you stayed the same, reduce your calorie target a little.
If you went down but are feeling incredibly tired every day, increase your calorie target a little.
If you went down and are feeling good, keep doing what you're doing!

That is all there is to it. Exercise and all-around health is important enough that it's been mentioned plenty of times in this thread, but to answer your question: there is nothing that can stop a person from losing weight (with or without exercise) except his or her own lack of determination.

Making a lifestyle change to eat less food was extremely difficult for me. I was hungry constantly; it was agonizing. After a few weeks, it got noticeably easier. After two months, my body was completely conditioned to handle the lower quantity of food it was getting and hunger was relegated to the hour before mealtimes. If you can push through the initial shock of the change, you can do it. For me, every time I've ever "plateaued" or saw my weight loss stall out, it was because I was in denial about just how much I was overeating.

Please note that if you are severely undereating you will experience two negative side effects: loss of energy, and loss of muscle mass. Your body will break down muscle (in addition to fat!) to get the energy it needs if you aren't providing the needed calorie/protein intake.

For more information, check out the section on "Cutting" in this post: http://forum.bodybuilding.com/showthread.php?p=401681611#post401681611

I have zero energy...

yet another reason to exercise... just saying

http://longevity.about.com/od/lifelongfitness/a/exercise_energy.htm