calories in vs calories out in this subverse is all about losing/gaining/maintaining weight and in that context calories ARE all the same. However when it comes to what's healthier relative to another food (since there is no such thing as "unhealthy/bad food") then you have to start looking at the macronutrients (which make up the calories) and micronutrients (which provide the minor stuff your body needs like vitamins and minerals and phytonutrients etc, essentially the NON-major things). Pizza has barely any amounts of micros per unit or per whatever amt calories vs lean meat and vegetables of the same number of units or the same amount of calories. Pizza also has a different ratio of the four macros (yes four because fiber is a macro as well even though it falls under the carb category but your body requires a lot of it, and it can't even be digested and it has giant benefits mainly digestion and proper bowel movements, all according to the FDA so no bs here) vs lean meats or vegetables. Also every single food you eat causes a spike in blood sugar, some a bit more than others and especially if you haven't eaten in a while. Your answer is an opinion. A wrong one but you're entitled to one regardless. No biggie. It is the law of thermodynamics as well for a reason. Besides there is also chemistry, biology, anatomy, and physiology as well that all explain how the body works and how it breaks down food and how food turns into sugars and how body is involved with converting food into glucose and how insulin works, etc etc. LOONNNNNGGGGG ASSSSSSS SHIT for this reply lol