 We can choose carbohydrate-rich plant foods over animal foods to boost tryptophan levels, but ideally it would be more than just carbs. Since the main determinant of brain serotonin concentrations appears to be the ratio of tryptophan with others that compete with it for uptake into the brain, to maximize the mood-elevating effects of diet, one would ideally choose a snack with a high tryptophan to total protein ratio, which would mean primarily seeds, such as sesame, sunflower, pumpkin. Protein-sourced tryptophan as an efficacious treatment for social anxiety disorder, a pilot study. So what protein source did they use? Butternut squash seeds, because of their high tryptophan to protein ratio, as part of a randomized, double-blind, placebo-controlled crossover study of people suffering from sociophobia, also known as social anxiety disorder. And they found significant improvement in multiple objective measures of anxiety in those eating these squash seed bars. Before studies like this one, a change in the composition of intact dietary protein was not seen as a possible option for the treatment of common psychological disorders associated with low serotonin levels. But that's because they were using animal proteins, which can make things worse, not plants. If this is true, then those eating vegetarian should be golden and indeed this was the reason they used to explain why global mood was significantly better in the vegetarian than in the mixed diet group. It's all about carbohydrates and a huge tryptophan to protein ratio. The vegetarian group was instructed to avoid meat, fish, and poultry and to restrict intake of milk, milk products, and eggs to a minimum. And within three weeks, the vegetarian diet group had a significantly improved global mood.