How does an ectomorph's inherently higher non-exercise activity thermogenesis (NEAT) impact their required caloric surplus for muscle gain compared to other somatotypes?

An ectomorph is a somatotype characterized by a lean, slender build, typically with a faster metabolism and a lower propensity for fat storage, making it challenging to gain weight. Non-exercise activity thermogenesis (NEAT) refers to the energy expended for all physical activities that are not sleeping, eating, or structured exercise. This encompasses spontaneous movements such as fidgeting, standing, walking, typing, and other unconscious daily activities. Ectomorphs often exhibit inherently higher NEAT, meaning their bodies unconsciously expend a greater amount of energy through these subtle, non-exercise movements throughout the day compared to other somatotypes like mesomorphs or endomorphs. This elevated NEAT directly contributes to a higher total daily energy expenditure (TDEE), which is the total number of calories an individual burns in a day from all sources. To achieve muscle gain, the body requires a caloric surplus, meaning it must consume more calories than it expends, to provide the necessary energy and building blocks for muscle protein synthesis and anabolism. Because an ectomorph's inherently higher NEAT results in a greater overall calorie expenditure daily, they must consume a significantly larger absolute number of calories to establish and sustain the necessary caloric surplus required for effective muscle growth. For instance, if a mesomorph needs to consume 500 calories above their maintenance to gain muscle, an ectomorph might need to consume an additional 300-500 calories daily just to reach the same maintenance level as the mesomorph, before even adding their own 500-calorie surplus for muscle gain. Consequently, the required caloric surplus for an ectomorph to achieve muscle gain is substantially higher due to their elevated NEAT.