Many people will say that reducing portion sizes will help you to lose weight. This may sound obvious, but in practice it may not be so easy. You firstly need to be aware of how much you are eating as you will not be able to cut it down otherwise. You can do this by writing down what you are eating for a while, perhaps a week.
Another way is to take a look at how much food is actually on your plate when you serve it up. Some people suggest splitting what you would normally eat between two plates and then put one in the fridge for the following day. This may be difficult for some people as they will find it hard to resist the food and just warm it up and eat it or they will not want to have the same meal in such close succession.
Of course, you could always cook less food, but it can be surprisingly difficult to get in to the habit of doing this when you are used to cooking large meals. Cutting down on snacks can also be difficult as sometimes you do not even realise what you are eating. Try to buy less unhealthy snack food and this could help. Perhaps start by snacking on healthier food and even trying to see how long you can go between eating, perhaps trying to cut the snacks out altogether.
You may find that you can reduce the amount that you are eating more and more, as you get used to eating less. It can be easier to do this gradually rather than cutting down by a large amount to start with as you will find this difficult to get used to and you may find that you get hungry and therefore find it hard to stick to. By reducing portion sizes you will still be able to eat the foods that you like but just have less of them. It should help you to lose weight as your calorie intake will be lower.