Why Does Pho Make You Sleepy? Exploring the Science Behind This Common Phenomenon

Pho, a Vietnamese noodle soup, is a popular dish enjoyed by many people around the world. However, some individuals may experience drowsiness and fatigue after consuming this delicious meal. As someone who has experienced this phenomenon myself, I became curious about the science behind why does pho make you sleepy.

After conducting some research, I discovered that the reason behind pho-induced sleepiness is due to a combination of factors. Firstly, the warm and comforting nature of the soup can cause a relaxing effect on the body, making it easier to fall asleep. Additionally, the high carbohydrate content in the noodles and the broth can cause a spike in blood sugar levels, followed by a crash, which can also contribute to feelings of drowsiness.

The Science Behind Pho and Sleepiness

The Science Behind Pho and Sleepiness
The Science Behind Pho and Sleepiness

The Composition of Pho

Pho is a traditional Vietnamese soup that consists of broth, rice noodles, herbs, and meat. The broth is made by simmering beef bones, onions, ginger, and spices for several hours. The noodles are made of rice flour, and the meat can be either beef or chicken. Herbs such as cilantro, basil, and lime are added to the soup for flavor.

Pho is a nutrient-dense food that contains a variety of vitamins and minerals. It is a good source of protein, which is essential for building and repairing tissues in the body. The broth also contains collagen, which is a protein that supports skin, hair, and joint health. The rice noodles provide carbohydrates, which are the body’s primary source of energy.

How Pho Affects the Body

Pho is a warming and comforting food that can have a calming effect on the body. The warm broth can help to soothe the digestive system and reduce inflammation in the body. The herbs and spices in the soup can also have anti-inflammatory and antioxidant properties.

Pho is also a hydrating food that can help to replenish fluids in the body. The broth contains electrolytes such as sodium and potassium, which are essential for maintaining proper fluid balance.

Why does Pho Make You Sleepy?

Pho can make you sleepy due to the presence of tryptophan, an amino acid that is found in meat. Tryptophan is a precursor to serotonin, a neurotransmitter that regulates mood and sleep. When tryptophan is consumed, it is converted into serotonin, which can make you feel relaxed and sleepy.

In addition to tryptophan, the warm broth and comforting nature of pho can also contribute to feelings of relaxation and sleepiness. The carbohydrates in the rice noodles can also help to increase the production of serotonin in the body, which can promote sleep.

Overall, pho is a delicious and nutritious food that can have a calming effect on the body. Its combination of warm broth, rice noodles, meat, and herbs can provide a variety of health benefits, including improved digestion, hydration, and relaxation.

Factors that Contribute to Pho-induced Sleepiness

Factors that Contribute to Pho-induced Sleepiness
Factors that Contribute to Pho-induced Sleepiness

Amount of Pho Consumed

The amount of pho consumed can have a significant impact on how sleepy it makes you feel. Consuming a large bowl of pho can cause a feeling of fullness and lead to drowsiness. The body uses a lot of energy to digest a large meal, which can make you feel tired. Additionally, the high sodium content in pho can also contribute to feelings of fatigue.

Time of Day

The time of day that you consume pho can also affect how sleepy it makes you feel. Consuming pho in the evening or at night when the body is naturally winding down can exacerbate feelings of drowsiness. On the other hand, consuming pho in the morning or at lunchtime when the body is more alert may not have the same effect.

Individual Differences

Individual differences can also play a role in how pho affects your sleepiness levels. Some people may be more sensitive to the ingredients in pho, such as the MSG or the spices used, which can cause feelings of drowsiness. Additionally, some people may have a slower metabolism or digestive system, which can make them feel more tired after eating a meal.

Overall, the amount of pho consumed, the time of day, and individual differences can all contribute to pho-induced sleepiness. It is important to be mindful of these factors and listen to your body’s signals to determine if pho is causing you to feel more tired than usual.

How to Enjoy Pho without Feeling Sleepy

How to Enjoy Pho without Feeling Sleepy
How to Enjoy Pho without Feeling Sleepy

Tips for Eating Pho

When it comes to eating pho, there are a few things you can do to reduce the likelihood of feeling sleepy afterward. Here are some tips:

  • Go easy on the noodles: One of the main reasons pho can make you feel sleepy is because it’s a heavy, carb-heavy meal. To reduce the amount of carbs you consume, try eating less of the noodles in your pho bowl.
  • Choose leaner meats: Fatty meats like brisket and flank can also contribute to feelings of sleepiness. Try choosing leaner meats like chicken or shrimp instead.
  • Add more vegetables: Vegetables can help to balance out the heaviness of the noodles and meat. Load up on bean sprouts, basil, and other veggies to make your pho bowl more nutritious.
  • Drink plenty of water: Staying hydrated can help to combat the sluggish feeling that pho can sometimes cause. Make sure to drink plenty of water before, during, and after your meal.

Alternatives to Pho

If you’re looking for a lighter meal that won’t leave you feeling sleepy, there are plenty of alternatives to pho that you can try. Here are some ideas:

  • Bun cha: This Vietnamese dish consists of grilled pork, vermicelli noodles, and fresh herbs. It’s a lighter option than pho but still packed with flavor.
  • Banh mi: This Vietnamese sandwich is made with a crispy baguette and filled with meat, pickled vegetables, and fresh herbs. It’s a great option for a quick, on-the-go meal.
  • Summer rolls: These fresh, light rolls are made with rice paper, vermicelli noodles, and fresh vegetables. They’re a healthy and delicious option for a light lunch or snack.


In conclusion, pho, like many other foods, can make you sleepy due to a combination of factors such as tryptophan, carbohydrates, and warmth. 

However, it is important to note that everyone’s body reacts differently to food, and there may be other factors at play. Additionally, the cultural and social context in which we eat can also have an impact on our experience with food.

Perhaps the real question we should be asking is not why does pho make you sleepy, but rather why we feel the need to explain or justify our natural bodily functions. 

Eating is a basic human need, and feeling sleepy after a meal is a common and natural response. Instead of trying to fight against our body’s natural processes, we should embrace them and listen to what our bodies are telling us.

About Mai Tran

As Mai Tran, the author of the Bunker Vietnamese website specializing in Vietnamese food, I would like to extend a warm welcome to all my readers. Growing up in a Vietnamese household, I have always had a deep appreciation for the rich and diverse flavors of Vietnamese cuisine. Through my website, I aim to share my passion for cooking and my cultural heritage with the world. From traditional recipes passed down through generations to modern twists on classic dishes, my website is a celebration of the vibrant and delicious world of Vietnamese food. Join me on this culinary journey and discover the beauty and complexity of Vietnamese cuisine.

Leave a Comment