One of the best things you can do for your health is to drink more water, ideally two litres a day (at least). Not only will this help keep you hydrated, but it will also make it a lot easier for your body to flush out any toxins to help prevent them being stored as fat.
Try to keep your food as close to it's natural state as possible. Ready meals are loaded with various chemical preservatives as well as salt, sugar, and I dread to think what else. Although convenient, they are absolutely no good for your health. If you rely on ready meals due to time limitations, make your own meals in advance and store them in the fridge / freezer. This way you are in complete control of what you eat.
Always read the labels on the packaging of any foods you buy; don't fall for cheap advertising tricks - just because something claims to be natural, that does not mean it is. If it is processed, it is not natural.
Replace refined (white) foods like rice, pasta, bread with the wholegrain alternative and limit them to two portions a day (a portion being the size of the pal of your hand). Refined foods contain no nutrition at all, they are just extra calories. The same goes for sugar - it is nutritionally unnecessary and just increases your calorific intake. If you really cannot cope without some sort of sweetener in your tea / coffee, then get yourself some agave nectar. Artificial sweeteners, as popular as they are, do more harm than good. There is plenty of info available on the harmful effects of these chemical sweeteners so I don't need to go into it.
Never skip meals as this messes with your metabolism and stops your body from burning calories as efficiently as it should.
When you're cooking, be very careful not to add too much salt. Although a little salt is necessary, most people consume dangerous amounts.
Increase your intake of vegetables - most of what is on your dinner plate should be vegetables, aim for three quarters of your meals to be veg. Also, increase your intake of fruit in its natural form.
Dairy - even reduced fat dairy options are still extremely high in saturated fat. Keep these to a minimum. Fats themselves are not bad, in fact they are necessary for us all - our bodies cannot burn fat without being supplied with fat. Not all fats are equal though. Saturated fats (normally of animal origin) are bad, other types of fat (plant origin) are good and will benefit you when consumed sensibly. The fat exception is coconut oil as this is a saturated fat that is good for you.
Fruit juices should be avoided by anyone trying to lose fat. Although fruit itself is good for you, when it is turned into juice it is basically just sugar. Anything with such a high sugar content, even natural sugar, will give your body a massive dose of energy which, unless used by being very active, will turn into fat.
Although it is good to avoid excess calories, try not to obsess about calorie counting. If you eat clean (no junk / refined foods) the fat will come off; the less fat on your body, the less toxins your body will contain and the more efficient it will be.
It is nutrients our bodies need, not calories. The best way to plan meals is to think about what will give you the highest amount of nutrients.
A wonderful site for further information is -