Wot UnclePat said. I've added a few other meandering thoughts below.
Running 5k three times a week, combined with slightly more sensible eating lost me 2 stone about 18 months ago. The recent festive season has undone a bit of that good work, so I'll be restarting again in earnest this week.
Nearly everything I cook avoids creams, butter, coconut milks, large quantities of oils, fatty cuts of meat, and the like. I try to keep to foods containing lots of chilli, bulked (in a non obvious way) with veg, containing lean proteins.
Do some weight work - gram per gram muscle tissue burns more calories than pretty much any other tissue (brain excepted). More muscle tissue = higher calorific burn. You don't need to do anything mental, nor do you need any specific equipment. Sit ups/push ups/lunges will all work.
Weigh your food - in particular your portions of meats and carbs. 1 serving of pasta is significantly smaller than you think it is. 1 serving of steak is a *lot* smaller than you think it is. Leave your scales on the kitchen counter and try this for a week - you'll get your eye in on what a portion is quite quickly.
Read labels. It can be alarming what you think is good for you, but which actually isn't.
Brush your teeth early in the evening, and after your dinner. You'll be less inclined to snack (a friend of mins swers by this).
Plan your meals in advance (as much as possible), and always have the basics in to make something - even if it's beans on toast. Leaving meals to chance means you *will* eat either bad food, too much food, or utterly unsatisfying food.
Deny yourself nothing, but moderate the bad stuff. "Dieting" doesn't work. Eventually, you'll fall off the wagon and the weight will pile back on. Try to adopt a more "wholistic" approach to it all - exercise, eating, cooking, everything. It's been proven to work more successfully in the long term.
Low fat butters and spreads are crap. Don't bother with them. Just try to use less of the good stuff.
Ditto sugar replacements.
Here are a few suggestions of dinners I cook on a regular basis:-
>Spag bol (I use a variation on a weight watchers recipe that's very tasty)
>Chilli - there's nothing in it except lean mince, tomatoes and kidney beans
>Pepperpot beef - seasoned beef, with kidney beans, peppers, white pepper, chilli, powdered ginger, garlic etc (from The Butlers Pantry cookbook)
>Chilli chicken ramen - nothing in it but stock, some noodles, veg.....
>Currys - lots and lots of them, in particular vegetable curries - all tomato based, none containing creams or coconut milk. I cook a lot of indian curries. I always use clarified butter, but I generally half the quantity called for in most recipes. It generally work out at about 1 - 1.5 teaspoons of clarified butter per person. Curry is an excellent way of maximising taste, minimising calories, if done correctly. The drop in fat does diminish taste slightly, but I think it's well worth the sacrifice.
>Spicy beanburgers, spicy turkeyburgers, harissa spiced chicken burger, spicy anything burger, all home made. Served with salsa, very small amounts of guacamole (avocado is enormously high in calories).
> Seared salmon with spicy puy lentil salsa (awesome:- basically, it's regular salsa but with puy lentils added in).