This is one reason why I think that carb cycling is good. You see eating enough protein, many carbs and many fats is the diet that is supposed to increase your testosterone and build muscle (combined with enough sleep). But such a diet is only possible when bulking. When cutting you need to either lower carbs or fats. Lowering carbs will make your workout performance suffer and lowering fats will make your testosterone levels suffer (maybe). So here is where carb cycling comes into play, when cutting. The days when you exercise you should follow high carbs and low fats but at the rest days – high fats low carbs. In general carb cycling is not necessary, but maybe it will help keep testosterone levels high while cutting.
The effect of a nutritional source of tryptophan on dieting-induced
changes in brain 5-HT function.
Psychol Med. 2003.
Dieting in healthy women results in a decrease in the availability of tryptophan, the amino-acid precursor of serotonin, for brain serotonin synthesis. This is associated with increases in the prolactin response to serotonin drug challenge suggesting a 'supersensitivity' of serotonin neuroendocrine responses. The aim of the study was to assess whether increased tryptophan intake during dieting would prevent the changes in tryptophan availability and serotonin neuroendocrine function. Fifty female subjects underwent a 1000 kcal daily diet for 3 weeks. In the final week of the diet subjects were randomly allocated to receive either nutritionally-sourced tryptophan ( g daily) or placebo in a double-blind, parallel group, design. Tryptophan supplementation failed to modify the dieting-induced reduction in fasting tryptophan availability to the brain. However, in contrast to placebo-treated subjects, subjects receiving additional tryptophan did not show enhanced prolactin responses to intravenous tryptophan challenge. The decrease in tryptophan availability produced by dieting may be due to increased tryptophan metabolism rather than decreased tryptophan intake. While tryptophan treatment did not increase fasting tryptophan availability it may have modified the effect of dieting on brain serotonin function. Further studies will test the effect of tryptophan has consequences for the effectiveness of dieting as means of weight control.