These findings provide support for the controversial ‘extreme male brain’ theory of autism, a disorder characterized by impairments in social interaction and a tendency to engage in repetitive behaviours. This theory posits that autism represents an extreme version of the normal male brain profile that is characterized by an increased systematizing ability and a reduced empathizing ability in comparison to females. The pathological impairment of empathy in autism may therefore arise from excessive “male” hormone levels during development. Accordingly, reduced 2D:4D ratios have been observed in autistic individuals and in their first-degree relatives.
Another thing to consider is that when you eat a high-fat diet, you typically need to reduce your consumption of carbs. The problem is, carbohydrates also have an impact on testosterone levels. It all has to do with the cortisol hormone. Cortisol and testosterone are inversely linked, meaning that higher levels of cortisol will result in lower testosterone levels and vice versa. A low-carb diet, especially combined with doing regular exercise and maintaining an active lifestyle, is a recipe for increased cortisol production.