Interestingly, while calories do matter, they only matter in regard to how the body metabolizes the particular macronutrient. As an example, imagine a daily consumption of 3000 calories in beef, avocado oil, broccoli, butter, and cheese. Now imagine that same day, but replace the food with thirteen 16 oz bottles of Mountain Dew. Roughly the same caloric content. But VASTLY different biochemical process in the metabolism. The former would result in weight loss if sustained over time. The latter would result in increasingly obesity over the same period of time.