What does weight have to do with missed periods?

Dr Sarah Jarvis MBE Meet with a dietician to create a plan for gaining weight. If you're missing your period due to a low body weight, talk with your GP and dietician about healthy ways to put on weight. Excess body fat can cause your periods to become irregular. Meet with your GP or practice nurse, who may be able to refer you to a dietician to discuss ways to lose weight. Even losing 5% of your body fat can help get your cycles back on track. This can be particularly helpful if you're dealing with PCOS. https://patient.info/health/periods-and-period-problems/features/missed-period-irregular-period-reasons