Most of my success in losing 60lbs over the last year and a half was all due to a spreadsheet I created.
If it goes in my mouth, then I first count the calories and put it into my spreadsheet.
Some simple truths about weight...
1.) Living being consume energy.
2.) Without calories a person would eventually die.
3.) If you consume more calories than your body can use, it stores that extra energy as fat.
4.) Exercise burns calories, but isn't a total solution. (see #3)
5.) If you consume less calories than your body needs, then you will lose weight.
6.) Whether you are trying to gain weight, maintain weight, or lose weight, you should always focus on EATING HEALTHY!!
7.) If you keep track of your daily caloric intake, and your weekly weight, you can start making *informed* decisions about your DIET and EXERCISE to impact your weight one way or the other.
8.) Experts recommend only losing 1-2lbs per week. (Anything more is either water weight loss, and is also likely hard on your health, and not sustainable.)
9.) If you track your calories each day in a spreadsheet, and your weight on a weekly basis, then you can start catering what you eat to meet your caloric and weight goals and still eat healthy and delicious food.
10.) Counting calories in a spreadsheet helps you to see WHICH FOODS give you the most/least bang for your buck!
When I'm starving and quickly approaching my daily caloric max, I turn to things like: apple (100 cal), carrots (35 cal), bok choy (10 cal), squash (30 cal), orange (70 cal), banana (100 cal), can of tuna in water (100 cal), and so on.
11.) Reduce carbs, reduce processed grains/foods, eliminate sugars, eat tons of fruits and vegetables, and eat lots of healthy proteins (e.g. tuna in water, chicken w/o skill, fish, etc)
12.) Have a "fat day" once a week or once every two weeks depending on your body and progress.
(I often lose more weight a week or two after I have a Little Caesar's pizza one Friday than if I just starve myself for weeks on end! Having that "fat day" tricks my body/metabolism into thinking all is well and that I'm not secretly starving to death on a desert island!)
13.) Read up on "planks"
14.) Read up on exercises which use your own body weight.
15.) There's lots more, I suppose, but these things above have worked for me, and I believe them to be pretty solid advice. (And they have worked well for someone who CANNOT exercise much due to a bad knee, bad back, etc.)
Good luck, and know you can reach your health and weight goals with a good game plan, regular feedback/data, and perserverance!!