Will weight loss and fitness scare away menstruation?: Sports nutrition and amenorrhea

Will weight loss and fitness training scare away menstruation?

A young woman asked me, "Do you think that losing weight and exercising will scare away menstruation?"

I was a little confused: "What do you mean by that?"

The woman said somewhat shyly, "My periods used to be very regular, but this year I missed them for three consecutive months from May to August. I had no choice but to go to the hospital. After receiving hormone injections, my period came, but the flow was very light. And now, after stopping the medication, my period hasn't come again this month."

I immediately understood that this woman's amenorrhea was caused by dieting.

She continued, "I don't know if it's a problem with my diet or exercise. I think my diet is quite reasonable; I even eat more than many of my female classmates who are trying to lose weight. How come my period just 'went away' like that!"

I asked, "What do you eat? And how do you exercise?"

She replied, "In the morning, I have a bowl of porridge, a boiled egg, and a small dish of cold side dishes. For lunch, I eat half a bowl of rice, plus one meat dish and one vegetable dish. In the afternoon, I eat a small apple or a large tomato. At 5 pm, I make a bowl of oatmeal porridge and then go to the gym to exercise for an hour under the guidance of a trainer, combining cardio with resistance training for muscle building. Considering that I want to build muscle, I also drink two scoops of full-fat milk powder in the evening. Since January of this year, I go to the gym three days a week, and on the other three days I go for a one-hour run, with Sunday as my rest day."

I said, "You're definitely not eating enough. Your breakfast of porridge, eggs, and vegetables only contains a small amount of starch, about 8 grams of protein. Your lunch was just half a bowl of rice, and I don't know how much meat you ate; a single serving of meat in the cafeteria is probably not much, so the total protein intake for that meal is unlikely to exceed 20 grams. Your evening bowl of oatmeal is mostly water, less than 50 grams of solid food, with less than 5 grams of protein. Even with two scoops of whole milk powder at night, equivalent to 200 grams of milk, the protein is only 6 grams. Your total daily protein intake is less than 40 grams, far below the minimum daily protein requirement of 55 grams for adult women with light physical activity. Your starch intake is too low, and your total energy intake is also far below normal. You also exercise for an hour every day, so of course your body will feel like it's not getting enough."

The woman said, "The gym instructor said that to lose fat, I should eat less staple food, preferably low-glycemic index staple food, but the cafeteria doesn't have whole grains, so I can only eat oatmeal porridge for dinner. The instructor also said that I need to replenish protein after exercise, which is why I drink whole milk powder!"

I asked again, "Did the coach tell you that you should consume this little energy every day?"

She said, "I consume quite a lot of energy every day! I measured my basal metabolic rate at the gym, and it says I need 1250 kcal per day. This diet I designed provides 1200-1300 kcal, which I calculated by checking food calorie charts online. Since the amount I eat is enough for my body's energy needs, there shouldn't be any problems!"

Seeing her confident demeanor, I had no choice but to patiently explain: "The so-called basal metabolic rate is the energy required to maintain basic life functions under conditions where you do nothing, lie in bed motionless, your mind is calm and you're not thinking, your stomach and intestines aren't digesting, your emotions are quiet, and the ambient temperature is neither too hot nor too cold. Do you spend your days lying in bed? Don't you study, work, or think? Don't you sit up, walk, or exercise? Don't you digest food? All of these require extra energy! A normal-weight adult woman with light physical activity should consume about 1800 kcal of energy per day. You've added an hour of exercise every day, which will increase energy expenditure by about 300-400 kcal. Think about it, how can consuming only 1200-1300 kcal per day be enough?"

The woman said, "But I want to lose fat. Doesn't losing fat require eating less? How can I lose fat if I'm maintaining an energy balance?"

I said, "Losing fat does require a negative energy balance, but you also need to build muscle at the same time. Your body will sense that your muscles are too weak and need to build more. Building muscle requires protein, and your protein intake is too low-not even meeting your body's basic needs. How can you build muscle? Maintaining a normal menstrual cycle also requires nutrition and protein. With severe nutritional deficiencies and a severe protein shortage, your menstrual cycle will inevitably be affected."

She asked, "Isn't menstruation a basic physiological need for women?"

I said, "That's not true. Think about it, if you encountered a famine and couldn't even get enough to eat, would you consider having a child right away? Compared to survival, reproduction is secondary. In cases of severe malnutrition, the body will temporarily enter a 'survival' mode of conservation, and reproductive function will resume once nutritional status improves."

"Every woman's body is different, and their daily food intake varies. Even if someone eats less than you, they may not immediately experience menopause. Generally speaking, women who have received adequate nutrition from childhood, have sufficient muscle mass, and a larger daily food intake can withstand longer periods of dietary restriction. Women who are inherently weaker cannot withstand even slight dietary restrictions. Exercise increases energy and nutrient consumption, so if you eat the same amount of food, increasing your exercise will make you more likely to experience menopause than someone who doesn't. Therefore, don't blindly compare yourself to others in terms of who eats less."

She said she basically understood, and then asked, "Should I stop exercising and running? My mom heard that I've stopped menstruating and calls me every day urging me to eat more and not to continue exercising. As a result, I stopped exercising for a week and ate whatever I wanted every day, and my weight suddenly increased by 1.5 kilograms."

"Honestly, I'm so devastated lately, I feel like crying every day. I've been working out so hard for so long, and I was finally starting to see results, but now it's all gone back to normal. It's so upsetting. But if I don't stop exercising, my period keeps coming back, and what will happen to my fertility in the future? Just thinking about it makes me so sad..."

I comforted her, saying, "Actually, exercising for an hour every day and having a normal period are not contradictory. The key is to have sufficient nutrition. First, forget about your weight. You've been dieting for several months, so it's inevitable that you'll gain weight temporarily after resuming your normal eating habits. Once you've replenished your nutrition, you'll have more energy to exercise, and you'll become a healthy and slim beauty."

"However, it's not about consuming the highest energy in food. The focus should be on protein, specifically meat, eggs, and dairy. Aim for at least 200 grams (dry weight) of staple foods daily, and avoid sweets, fried foods, and all kinds of processed snacks. You need to repair the useful parts of your body-the protein in your blood, internal organs, and muscles-not increase fat. Therefore, avoid foods that only lead to weight gain and don't promote vitality. Otherwise, the rebound weight gain will usually be primarily fat, primarily deposited in the waist and abdomen, resulting in a higher body fat percentage than before you started dieting."

Since this lady can only eat in the cafeteria and cannot cook for herself, I suggested that she increase her staple food by 50 grams in the morning and eat two eggs; eat a bowl of rice at noon, and in addition to vegetables, she must also have a serving of meat; after exercising in the evening, drink a bowl of milk oatmeal porridge, add some fruits and vegetables, and drink a glass of milk at 9 pm.

In fact, I've heard similar stories from hundreds of women. Studies abroad have long found that many female athletes suffer from insufficient nutrition during exercise, which can lead to anemia, and menstrual irregularities are not uncommon. These problems can be avoided by improving nutrition.

Hopefully, those who have had similar experiences can learn from this, better appreciate their health, and eat well and correctly while strengthening their physical exercise.