If you’re no longer having your period and aren’t post-menopausal, this means your body isn’t getting enough calories to function properly. If this is the case, you’ll need to switch your goal from weight loss or maintenance to reverse dieting or muscle gain. Both of these goals will increase your calorie intake, and when calories get high enough, your normal menstrual cycle should be restored.
To decide which goal you should choose, you’ll need to ask yourself whether you want to gain weight or not. If you want to gain weight, select the muscle gain goal. If you don’t want to gain substantial weight, select the reverse diet goal.
Once you’ve been on your new goal for a few months, it’s likely that you’ll start having your period again. Make sure to maintain your new higher calorie intake for at least 6-9 months and consult with your doctor before changing your goal to weight loss again.