If you cut and paste the following search string into Google ? "
Calorie Calculator - Daily Calorie Needs" you will get a few results that can help. You can learn a lot by counting the calories of what you eat. Something I may get back into myself, however with more focus on nutrition.
Unfortunately there is no easy way when dealing with processed foods, especially those designed for taste. I would recommend learning to use/cook/soak/blend wholegrain rolled oats with fresh fruit and a bit of honey. There are more complex combinations and methods with such whole foods. However in the interest of keeping it simple just learn to make outs in water with skim milk and used natural sweeteners like honey.
Start eating for health and less for taste ... eventually your buds will change so that fruit and vegetables become your friends. It's said that for a healthy body, most of what we eat should be fruit and veg.
The hard part is changing ones taste. Not an easy thing to do with food that is designed more for pleasure than it is for health. Once you come to understand this process with process foods; then it becomes a little easier to make the break. Make the slow changes so that you will not give up. ...Or go full steam into it and discover just how much fun it can really be when eating for health. Know what you really want and ask yourself if your really willing to do what it takes.
How much and what type of foods are you eating from day to day? If you can give a list of the foods you typically eat, then perhaps it may be better to give suggestions with regard to a gradual change.
SUGAR is a great place to start and anything that's made with it. But will have a lot to do with just how much you want to lose weight Vs sticking with taste.
I'm big on self motivating and being real with what one really wants.
If your unable to choose and prepare for yourself, I think your issue will come down to what you mum cooks.
Ask your mum to buy some oats, and more fruits. Tell her about your intention to loose some weight and about the foods you would like begin eating. Just don't expect everyone to be supportive when making healthy changes. Or if you mum already eats healthy, then she might be delightful surprised ... OR maybe mum will be interested in making healthier choices as well.
Hard to say without knowing the circumstances.
Just change what you are able to do. Giving up sugar is the place to start.
