OK...I realize I am one of the skinny Celiac's but I work out at a gym with a personal trainor and the vast majority of the women at the gym are not like me. They are there to lose a lot of weight and many of them are middle aged......like me. The things I have learned about maintaining weight and gaining muscle are good for losing weight too and followed by the larger ladies trying to lose weight.
Protein is your friend and should be the first thing on your plate in the morning. That means eating things for brekkies that you are not used to eating for brekkies, like turkey and veggies. Eggs are good also and they do NOT raise cholesterol.
Limit those carbs but you do need to eat some healthy ones. Eat the ones that don't come with a sugar hit. Yes, sugar makes you fat, plain and simple but it is OK to eat a little, if you are active. Unless it derails your diet, eating a small amount is OK.
Weight train. This is so important as you age and will boost your metabolism, which becomes slower and slower with each passing decade. I cannot tell you how well it works for weight loss, coupled with a good diet. I have seen women who swear they can NEVER lose weight, turn around and after 6 months, they have lost 40-50 pounds. It's the number one exercise for burning calories. I can eat a lot of food for my size because I weight train.
Lastly, eat every 3 hours approximately, no exceptions. I mean small, healthy snacks and keep total calorie count at the right amount for your size. Eating that often actually keeps your metabolism ramped up. Fasting or not eating enough slows it down. So, eat brekkies, snack, lunch, snack, dinner and then small snack but not right before bed. This really works......I have seen it many times over and none of these women are complaining they are hungry. Just make sure the snack portion is not too large....5 or 6 almonds and a small piece of fruit. It doesn't take much to keep you feeling full.
Remember, you burn more calories doing nothing with more lean muscle mass. Having more body fat slows down your metabolism. This is why men burn more calories than women do, at rest. They have more muscle mass.
Good luck, everyone!