Unless you really do have a medical condition, you're hungry because you're not eating the right types of food. Plus 1000 is super low for a guy. But even at 1000 a day, you could be eating 10 cans of tuna! (probably not the most tasty, but I bet you wouldn't be hungry). But yeah you should definitely increase your calorie intake.
"These days I eat a bagel sometime int he morning, and a turkey sandwich for lunch, and for dinner, usually something like a TV dinner from Lean Cuisine. Some of those Lean Cuisines are tiny and I will eat two of them. I drink coffee throughout the day too and put a little bit of cream in it but no sugar."
First of all, a bagel is a really poor choice. All of the breads you consume should be whole grain or whole wheat (whole grain is better). And a Lean Cuisine is also a poor choice. A bagel and a lean cuisine will only make you hungrier throughout the day. And cream in your coffee? That's bad too. If you really want something in your coffee, try a tablespoon or so of Unsweetened Almond breeze almond milk instead of cream.
You should try as hard as you can to stay away from any frozen or pre-made meals. Most of the times these things are processed in ways and have ingredients in them that make you crave more food.
For one thing, in the morning, since you're a coffee drinker, drink a cup of coffee
before you eat anything. And try replacing your bagel with lean protein like fish or poultry breast and a piece of fruit or 1 slice of whole grain toast. I think banana's and cut up red apples are both great filling fruits. And make sure you're drinking a LOT of WATER throughout the day in addition to your coffee.
I don't know what your turkey sandwich is composed of, but try replacing it with a sandwich made of 1 slice whole wheat bread (cut in half) - be sure to read the ingredients of the brand you buy - and one whole can of tuna. I add vinegar and pepper to my tuna and even though that sounds gross, it actually makes it taste similar to the way mayonnaise tastes on tuna. You could also add lettuce and tomato or any other veggies. But don't add any high fat, high sugar, or chemically condiments.
For dinner, make your OWN dinner. If you're a busy dude, premake meals for yourself. Like soup, make a giant pot of soup (with veggies and chicken breast) that will last you several days (and if you don't know how to cook #1, learn. But #2 soup is easy. Just add a lot of water, veggies, and raw meat, in a bowl and I actually make mine in a big bowl in the microwave cooking for about an hour.) You can have several servings of this soup and it's still low calorie.
sugar free gum is also a great appetite suppressant in my opinion.
I suggest #1, set out how many calories you can have PER MEAL and if you exceed that, eat lean protein like a can of tuna. And then you will be able to spread your calories out during the day. and #2 STAY AWAY from processed food and white/processed carbs. If you eat only natural foods, like fruits, vegetables, whole grains, and lean meats (fish and poultry breast) and nothing processed, you should have no trouble staying full and staying under your calorie limit (which you should increase anyway).
If you don't like the taste of natural unprocessed foods, then perhaps you're not as hungry as you thought
Good luck.