First of all I suggest that you work out how many calories you can have every day in order to lose weight. There are many sites out there that can help you calculate this, I don't know any in the UK or the US, but here in Australia I use Calorieking.com.au to work out and calculate my daily calories. I know someone from the US uses myfitnesspal.com which is also a good resource and free to use. This handy little calculator will help you figure out how many calories you need per day, and can allow you to input what you eat to figure out how many calories each food is.
Foodwise there are a million choices to have. Breakfast doesn't need to be just a grapefruit and an egg, you could have cereal and milk, muesli and yoghurt (both options can be paired with some fruit), toast, eggs on toast, omelette packed with vegies, an egg and bacon wrap, or a fruit smoothie. Try to add in some vegies or fruit with your breakfast to get up your intake. In Australia it's recommended to have 2 serves of fruit and 5 serves of vegetables a day. Good fruits for breakfast include melons, strawberries, grapefruits/other citrus fruits, blueberries, apples, sultanas, grapes and so on. Vegetables that are good on an omelette include peppers, mushroom, onion, peas, spinach and tomatoes.
For lunch you can have more than just sandwiches, you can make yourself up a yummy tuna salad without the bread, packed full of vegies, chicken/fish/beef and salad, stirfries, leftovers from dinner, a bit of cheese with whatever you're having is good too. You need plenty of calcium in your diet to prevent osteoporosis, so if you could have a bit with some meals this would be excellent. Try to pack in as many vegies as you can in this meal, even if it is a sandwich or a wrap.
Dinner again can be anything that you please, provided that you control your portions. You could have a yummy pasta bake packed full of vegies and lean meat, made with wholewheat pasta, a stirfry with a healthy sauce, a homemade curry (packed with lentils and beans as a good protein option instead of meat), baked fish is also a tasty option with homemade baked fries made from sweetpotato and regular potato and a side salad, soups and stews are also very tasty and can be made low calorie.
For snacks I suggest fruit, yoghurt, nuts (not too many though, they're high calorie, but very good for you, particularly almonds), light soups, and carrots/celery. I also suggest you leave room for a dessert if you have a bit of a sweet tooth, there are plenty of low calorie options out there in terms of ice-cream, cakes, jellies, and so on.
Basically in terms of food there are plenty of options available, you just have to get creative and maybe take some time to browse on the web for some low calorie recipes that you might like to try. In terms of nutrition though, you should have a look at your country's nutritional guidelines. In Australia it's recommended that you have 2 serves of fruit, 5 serves of veg, 1 -3 serves of protein, 1 - 3 serves of dairy, 6 - 10 serves of grains/legumes (potato is included in this area by the way), and 1 - 3 serves of good fats. Or something like that. Personally I don't get anywhere near that amount of grains because they can be very high calorie, and if you're getting plenty of vegetables you're also getting good carbohydrates that your body needs to survive. You can easily get at least 3 - 5 serves of complex carbohydrates by having a slice or two of wholewheat toast for breakfast, some beans in your salad for lunch, and some wholewheat pasta/potatos with dinner.
I hope this helps! Sorry for the long post!
Lisa.
