Never eat asparagus in a heatwave: 5 dehydrating foods to avoid

These are the dehydrating foods to dodge as temperatures soar

Photo of asparagus stems
(Image credit: Markus Spiske on Unsplash)

As temperatures rise, it's important to make sure you're adequately hydrated. Even if you're not planning on working out in the heat, you'll naturally be sweating more than usual, and it's easy to become dehydrated without even realising. We've already covered the most hydrating foods to eat in a heatwave (turns out, cucumber and radish are basically all water), so what foods have the opposite effect?

Here, qualified nutritionist Abi Roberts shares the dehydrating foods you should avoid, or at least balance out with plenty of hydrating liquids, in hot weather. 

1. Asparagus

Let's start with a surprising one. You might assume green veg is generally pretty hydrating, but asparagus is actually one of the least hydrating foods you can eat. That's because it's a natural diuretic. "[Asparagus] rids the body of excess fluid – meaning you need to wee more and you lose the fluid that you consume," explains Abi. "Diuretics also help your body to get rid of salt, so are useful for the body, but should be consumed in moderation."

2. Salty snacks

Less surprising: salty snacks are well known to have a dehydrating effect, with pork scratchings being one of the worst offenders. "Too much salt wreaks havoc on the kidneys, so limiting salt intake is important for overall health," explains Abi.

3. Sugar

There are loads of reasons why you should limit your sugar intake, and its effect on hydration is just one of them. "When you consume sugar, the kidneys react similarly to when they encounter salt," says Abi. "They pull water from other parts of the body, as the kidneys don’t want excess sugar in your bloodstream."

4. Cured meats

"Cured meats are often heavily coated in salt, with gammon being a particular offender," explains Abi. "The kidneys overcompensate when there is too much salt in the bloodstream, and pull water from elsewhere in the body, leading to dehydration." Picking on prosciutto in the sunshine might sound delightful, but make sure you're drinking plenty of water to balance it out. 

5. Bread

You're probably not too shocked to hear that pork scratchings and cured meat have a lot of salt in them, but you probably don't realise that bread could also be contributing to your salt intake. "Bread, although not terribly high in salt per slice, is one of the most common reasons behind people having too much salt in their diet," says Abi. If you're adding bread to most meals, or even snacking on bread-based things, that can add up to a high salt intake. "Limiting the amount of bread you eat will help reduce the sneaky salt that you didn’t even know you were consuming," she continues. 

Tips provided by Abi Roberts via Forbes Advisor (opens in new tab).

Ruth is currently on secondment as Sleep Editor for Tom's Guide and TechRadar. The role is an extension of her work on T3, where she ran the site's Wellness channel, which includes sleep, relaxation, yoga and general wellbeing. She was also Outdoors editor, reviewing and writing about everything from camping gear and hiking boots to mountain bikes, drones and paddle boards. She has tested more mattresses than her small flat can handle, and has had to implement a one-in-one-out pillow policy, for fear of getting smothered in the night.