This is the final post in a series of posts on popular diets and their effects on PCOS symptoms. So far, we have covered ketogenic diets, the Mediterranean diet, low glycemic index/load diets, and bean-based diets.

Given the rising popularity of plant-based eating, I thought it was important to include this way of eating. Unfortunately, the literature is seriously lacking on the topic. For nutrition interventions, we can best trust the results of randomized control trials. In these trials, a large group of people are recruited. Then half of the group is randomly assigned to the diet of interest and the other half are assigned to the control group (usually just continuing to eat as they had previously). For a plant-based diet intervention, we’d ideally recruit a large group of meat eaters, and then randomly assign half of them to switch to a plant-based diet. We’d measure important metrics before and after the intervention period to see if anything changed in those people who switched diets. We’d also track the same metrics in the control group, in case there are factors that affect both groups that also affect outcomes. For example, maybe the intervention spans the holidays and both groups end up eating more food than normal. We can net out the effects of these external factors by comparing the changes across the two groups.