The 4 Worst Beverages to Drink on a Plane—and What to Drink Instead, According to a Dietitian

Flying can take a significant toll on your body, especially when it comes to hydration and digestion, so it’s important to choose beverages that support hydration and comfort. Airplane cabins are known for their low humidity levels, usually hovering around 10% to 20% humidity, which is much drier than most indoor environments. This dryness and the potential for sitting still for long periods of time can lead to common issues like dehydration, bloating and fatigue. In fact, studies have shown that spending extended time in low-humidity environments like airplane cabins can cause your body to lose moisture faster. Additionally, when you’re at high altitudes, digestion slows down.

The drinks you choose during your flight can either help reduce those issues or worsen them. Staying well-hydrated with the right beverages can help reduce the risk of dehydration-related symptoms and fatigue, while avoiding certain types of drinks can prevent uncomfortable bloating and digestive discomfort. To make your next flight smoother, let’s take a look at the drinks to avoid while flying and some healthier options to choose instead.

1. Alcohol

Most people consume alcohol in social settings or during special occasions. For many, it’s also common to enjoy a drink while traveling, especially on flights where alcohol is often available as part of the in-flight service or menu. However, consuming alcohol on a flight can lead to dehydration and intensify feelings of fatigue due to its diuretic effect, which means it causes your body to lose more water, leaving you more likely to feel groggy and sluggish. Studies show that long-haul flights promote fluid shifts to the lower extremities and induce changes in blood viscosity, which may accelerate dehydration.

What to Drink Instead: Instead of alcohol, which can cause dehydration, consider treating yourself to a refreshing mocktail or sparkling water with a splash of fruit juice. This combination can give you the same celebratory feeling without the negative effects on hydration and energy levels.

2. Caffeinated Beverages

Caffeinated beverages, such as coffee, tea and energy drinks, are popular choices for many travelers, especially during those early-morning flights. However, caffeine acts as a diuretic, which can increase urine output and contribute to dehydration. This dehydration can lead to uncomfortable symptoms, and the caffeine may increase feelings of restlessness and anxiety. Research shows that in people with panic disorder, caffeine consumption raises the risk of having a panic attack and increases levels of anxiety and should be avoided or limited.

What to Drink Instead: Instead, try sipping on herbal teas or simply drinking water, which can help keep you hydrated and more comfortable throughout your flight. Herbal teas like ginger or peppermint can aid in digestion, which may help to combat bloating and other digestive issues.

3. Soda

Soda is another popular in-flight drink, but the carbonation in soda can lead to bloating and discomfort—especially at high altitudes. This trapped gas can expand due to the reduced pressure, intensifying feelings of fullness and discomfort, which is the last thing you want when you are in a confined space for a longer period of time. Additionally, some sodas contain high amounts of sugar, which can lead to a rapid spike in blood glucose. This feeling may initially make you feel more alert; however, this energy boost is often short-lived, followed by a “crash” that can leave you feeling even more tired and sluggish. The added sugar can also increase dehydration by making your body work harder to process it, ultimately leaving you feeling drained.

What to Drink Instead: If you’re craving something bubbly, consider sparkling water as an alternative, ideally one without added sugars or sweeteners. It still has a bit of fizz but without the heavy sugar load, and it’s generally gentler on your digestive system. Choose plain or sparkling water and add a slice of lemon or lime for a refreshing, hydrating alternative.

4. Milkshakes and Smoothies

Thick and creamy drinks like milkshakes or smoothies might be appealing for a quick treat or as a satisfying meal replacement before a flight, but they can pose challenges at high altitudes. The dense texture of these beverages makes them harder to digest, particularly in a pressurized cabin where digestion naturally slows down. The combination of higher fat content and heavier ingredients can contribute to feelings of fullness and bloating, which may quickly turn uncomfortable when you’re sitting in a small space for hours.

What to Drink Instead: If you want something creamy, consider a lighter option like a plant-based protein shake with low or no added sugars. This can help you avoid digestive discomfort and excessive sugar while still enjoying a satisfying treat.

The Bottom Line

When it comes to choosing the right drinks for your flight, a little planning can make a significant difference in your comfort and well-being. By opting for hydrating choices like water, herbal teas or refreshing mocktails, you can help combat dehydration, bloating and fatigue. Avoiding or limiting alcoholic or caffeinated beverages and those that are high in sugar will keep you feeling more energized and relaxed, making your flight experience smoother and more enjoyable. Next time you fly, be sure to make an informed choice to keep yourself hydrated, invigorated and feeling your best from takeoff to landing.