One test that gives the user a rating of their body composition is the BMI. The algorithm is based on whether the user is the right height for their weight. Generally this can work for those of average height and non gym users, as the skeletal muscle to fat ratio is lower.
For users that train regularly and have a higher muscle- fat ratio, the results can be absurd. For example- using myself, I get a result of being overweight despite being 6 ft 2 and a regular weights lifter. The idea is not to heavily rely on this test, if you’re trying to find out whether you need to lose a bit of weight or not then you would benefit from woking out your daily calorie expenditure, otherwise known as the Basal metabolic rate. This rate allows the user to ascertain how many calories they will burn a day at rest. That is the daily functioning of the body, without daily activities (gym, cleaning etc).
Try the link I have posted below. The result of this test will make it a lot simpler for you to ascertain how much or how little you should be consuming in terms of calories- the website also gives you a breakdown of where your calories should be coming from, based on the level of activity you provide.
If your overall goal is to lose some weight- then you need to eating less than the current allowance.
If your overall goal is to gain some weight- ie muscular mass, then you need to eat more than the allowance says you are on. The food MUST be of nutritional value, contributing to healthy anabolic growth- simply doubling your intake in pizza will add on weight- but NOT the good kind.