A few months ago a mother contacted me for her 17-year-old whose cycles had not settled into a regular pattern - she only had a few per year ever since she started - and who had significant hair loss after a summer Covid infection.
This girl had been an eager participant in the high school health class the prior year, and I knew she chose nutritious food, so this was a mystery I was happy to discuss. We met on Zoom and reviewed her recent health events, and used my Cronometer account (it's free- try it out!) to see what she was getting from her diet.
Here's what she was eating:
Breakfast - 3 eggs, 1 apple, peanut butter
Lunch - Leftovers from dinner, such as chicken, salad and vegetables
Snack - 1 orange, handful of cashews
Dinner - Chicken Korma, brown rice
I congratulated her on getting plenty of protein, fruit and vegetables. If more adults ate like this we would be better for it. And it was clear why her period were irregular - at the quantities she indicated for each food, it was only 1700 calories, and 120 grams of carbs. She wasn't walking around hungry because her blood sugar was staying steady, and she said there were times when she ate more, such as holidays when more sweets and different foods were in the house. I suspect this is when she would get a period.
She walked every day for nearly an hour, but her area is overcast much of the year, and often cold, and she walks her dog in the woods surrounding her house, so she's not getting much vitamin D from her time outside. This and the low calories provides some explanation of why she would experience hair loss after Covid without any comorbidities.
Two aspects that needed tackling to make her cycle regular were the overall calories, and the carbohydrates. She said that she didn't have much room for a larger quantity of food, so we talked about adding healthy fats at each meal - some butter or olive oil with the food she's already eating - and some nutritious carbs like sweet potatoes and dried mangoes when she has the appetite. This put her theoretical intake up to 2500-2600 calories and over 200 grams of carbs, which is more appropriate for a teen at a normal weight who walks an hour a day and helps out with a busy family. Perhaps she needs more, but this was the clear next step.
Since her diet was good overall, I told her to expect a cycle in about a month, allowing a couple weeks of higher calories to trigger ovulation, and then a couple weeks more for a period. And that's what happened - her body wanted to run a cycle, since that's normal for her age, and just needed more resources. Her hair is regrowing and she added a Vitamin D supplement, and when we checked in she said it hadn't been hard to add the extra calories, and she was feeling better overall.
I hope this story shows how increased calories can be the solution for irregular cycles in an otherwise healthy young lady, and a few small shifts can build on a good foundation. Checking nutrition periodically with an online calculator can be very helpful for seeing what changes to make.