Nutritionist reveals 5 foods you should avoid during a heatwave

By Sapphire Hope

As temperatures could hit 40 °C (104°F) in parts of the UK in the second heatwave this year, you may find yourself reaching for the foods you think will hydrate you and cool you down.

But Nishtha Patel, a clinical nutritionist, says some of the foods we think are the most soothing when it’s hot might actually be making us more dehydrated.

Here are five foods or drinks you should cut down on during this heatwave, according to a nutritionist.

1. Popsicles

Popsicles may just be one of the most common remedies when it comes to battling hot weather — which is why it is perhaps the most surprising that Patel says they aren't the fix we think they are.

Patel explains that in the heatwave, it is best to cut down on high-sugar snacks, such as popsicles, as they spike your blood sugar and leave you even more thirsty than before.

She says: “Popsicles and sugary flavors can give an instant cool feeling but cause a rapid spike in blood sugar.

“So your blood sugar will go up and crash and it can make you more thirsty shortly afterwards.”

2. Iced coffee

Many Brits will be reaching for ice-cold lattes during the scorching heat. Hot weather can leave you feeling sluggish and the caffeine boost partnered with refreshing milk might seem like the perfect answer.

However, Patel says too many iced coffees can leave you feeling far from awake and refreshed — as caffeine actually dehydrates you.

She says: “People might think they’re doing themselves a favor, having iced coffee, but they can be high in caffeine, which can then dehydrate you.

“You can have a little bit of coffee. I’m not saying don’t have any at all, but it has a mild diuretic effect that can make you urinate more.”

3. Potato chips

Before you go to sunbathe in the park with a bag of potato chips and dip, you may want to think twice — unless you have a large bottle of water to chug afterwards.

Patel says that even though potato chips might not feel harmful in the moment, their high sodium content will dehydrate you further.

She says: “Potato chips and fast food and white bread — they have low water content in them and they’re higher in sodium so they draw that hydration away from yourself.”

4. Ultra-processed meat

Like potato chips, ultra-processed meat such as chicken nuggets, pepperoni and some sausages have a low water content but are high in sodium.

The sodium actually draws hydration out of your body. Patel says it is best to cut down on it if you don’t want to feel dehydrated.

5. Chili peppers

Perhaps a more well-known food to avoid in the heat are chili peppers.

Spicy food makes you sweat and you risk becoming dehydrated if you do not replenish those fluids.

Patel explains the science behind the spice, saying that chilies have “fiery compounds in them called capsaicin that triggers a thermal receptor in your brain telling your body it’s overheating”.

She adds: “So from that heavy sweating which rapidly cools down your body temperature via evaporation, you’ve got to stay hydrated.”

Chilies make you feel physically hotter because they stimulate heat receptors which then increase your sweat.

Patel says when the “sweat evaporates it helps to cool the body down, so in that sense chilies can actually aid cooling, however, in a heatwave they make you sweat excessively” which can be unhealthy if you do not replenish those lost fluids.

She adds: “Especially in the heat they can trigger diarrhea or loose stools which can then cause you to lose more fluid.

“They can also worsen things like acid reflux or indigestion which can make you feel more uncomfortable for the hot weather, but with people that are used to them and in moderate amounts chilies are perfectly fine in a heatwave.

“You must replenish the water that you lose through sweating, that’s the key.”

So, what can you eat?

Patel recommends eating watermelon, cucumber, tomatoes and “watery” foods.

She says: “They’re hydrating you more. You lose a lot of electrolytes through sweat. You can do things like yogurt and kefir and obviously your lean protein.

“Coconut water is great during this weather because it’s naturally got some electrolytes and potassium and some magnesium.”