You're eating back all the calories you burn.
Exercise can help you lose when you're really using it to burn extra calories, (not as a reason to eat more).
You're relying on exercise alone to do the trick.
The best way to lose weight is to cut back on what you eat and increase your burn through exercise (not one or the other).
You're not eating as healthfully as you think.
If you're not meeting and/or you don't actually track your food/nutrition to see how it all adds up in black and white, don't make assumptions about how "good" you really do eat. (This is definitely something you need to get used too).
You're doing the wrong kinds of exercise.
The best exercise plan emphasizes cardio for calorie burning, but still includes strength training to preserve lean muscle, (both are important; neither option can do everything).
You're not being consistent enough.
Eat right and exercise as consistently as possible and apply both moderation and portion control when it comes to indulging. (I try to make it to the gym at least three times a week, start with cardio, then some weight training, to get rid of Bingo arms!!).
You're not measuring the right things.
Don't just rely on the scale to measure your weight loss. That number won't really tell you everything you need to know, (if your clothes are fitting better than your on the right track).
You have an underlying issue.
If you've truly tried everything mentioned here and more—and simply aren't making progress—it would not hurt to check in with your medical provider to see if any underlying issues are at play, (like Iv'e been saying; MENOPAUSE).
