You cannot outrun a bad diet. If you have aesthetic or performance oriented goals you're going to be fighting an uphill battle if you do not align your nutrition towards these desired outcomes. Not only will food strongly influence your body composition but enhance your performance and expedite your ability to recover from hard training.
"Healthy" eating vs "goal oriented" eating are not always the same. If you claim to be a "healthy eater" yet you haven't seen improvements in performance or body composition, then it may be time to adjust your way of dieting.
It will probably be best to find a professional you trust to guide you or consider something like the RP Diet App and follow the process with very strong adherence!
The philosophy, or science of nutrition is very, very simple: Energy in vs energy out. If you eat more calories than you use you will gain weight, if you do the opposite you will lose. Any other theory is wrong. You can make this a lot more technical but ultimately this is the information that most people need to learn.
The philosophy, as i said, is very simple, the hard part is carrying it out. You will need to sacrifice. This may include giving up some of your favorite foods, it may require financial adjustments to eat healthier, or add bulk to your diet (if seeking muscle gains). If what you're doing today is not working it's obvious that changes must be made. Fortunately, even modest sacrifices can often result in major benefits.
Eat less than you burn. Try to drop about 1% of your body weight per week in most cases.
If you eliminate entire food groups from your diet, it will net you a lower overall calorie consumption. In refusing to eat foods that you may strongly desire, the likelihood of adherence drops significantly. Barring medical requirements, it's generally not a good plan to eliminate food groups. Don't make dieting more painful than it needs to be.
Any form of fasting will net a lower total energy intake. If you stop eating after 5pm (another form of fasting), all this does is decrease the amount of time you allow yourself to eat netting a lower overall intake. A better idea for most people would be to spread out meals more evenly throughout the day to keep hunger at bay. No need to make yourself feel starved, and this should reduce cravings.
People can lose weight with "healthy" foods and "unhealthy" foods if calorie intake is controlled. Typically "healthy" foods provide more volume which keeps your belly fuller for longer. Full belly leads to less cravings which leads to greater sticktoitiveness.
Eat more than you burn. Try to gain about 0.5% of your body weight per week in most cases. Sorry to break it to you, but you can't chisel yourself a six pack while simultaneously putting on 10lbs of muscle per year. With muscle comes fat, if you gain slowly it should minimize the latter.
Being in a calorie surplus is harder than dieting to lose weight. You're full all the time, you're eating all the time and you're not gaining weight so you need to bump up your calories 10% more. You probably won't even like food for 3 months if done correctly.
If you're not gaining weight and that's your goal you're simply not eating enough regardless of what you think. Eating until your full is not going to cut it for most people. During a mass, I'm usually full before I even start eating!
Food choices shouldn't differ too much from fat loss or maintenance diets you're just eating larger quantities. It may be easier for some to toss in more calorie rich shakes or low volume high cal foods to more easily obtain the large energy intake.
Too many people place too high of value on supplements and not enough value in getting 3-6 substantial nutrient rich meals daily. Are you eating adequate protein for muscle building? Are you eating vegetables with each meal? Are you hungry/full throughout the day?
There is a place for some supplements but they are meant to "supplement" a solid diet. Most people with relatively little experience in logging calories and macros will not yield much benefit from supplements until the diet as a whole is locked in.
Beginners may opt to start with a whey or casein protein supplement to reach daily goals a bit easier but if you're seeking improved energy or accelerated fat burning then you probably need to address your eating and sleeping patterns more so than your pill routine.