The foods the royals are forbidden to eat - and the surprising ones they love

Being royal is no picnic when it comes to food. The Queen has had almost 70 years of state banquets, charity lunches and endless afternoon teas, so it's not surprising she's developed a few strict rules around eating.

She will never reveal her favourite foods, knowing that if she does, it's inevitable she'll be served the same dish everywhere she goes – but over the years, a few of her likes and dislikes have come to light.

Prince Charles is famously keen on ecology, and likes to eat seasonally and sensitively, with a life-long ban on foie gras, the French paté that's production is notoriously cruel to geese.

The Duke and Duchess of Cambridge differ in their tastes - Kate loves spicy food and curries whereas William 'struggles' with hot chilli, perhaps due to having grown up in royal palaces being served approved foods sanctioned by his father and grandmother.

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Harry is considered unfussy (a lengthy stint on army rations will do that) but Meghan was very open about her foodie tastes back when she wrote her regular lifestyle blog, The Tig.

So what are the family's banned foods - and what could they snack on all day?

Garlic and onions

Camilla, Duchess of Cornwall revealed on MasterChef Australia that "garlic is a no-no," adding that the family is requested to 'lay off the garlic' due to the impoliteness of breathing it over fellow VIPs and the public. Delicious though it may be, there's some smells a handful of mints won't shift.

According to former royal chef Darren McGrady, they are also expected to go easy on onions for similar reasons - and they are not the most digestible vegetables.

It's a big yes, however, to British vegetables such as spinach, courgettes and new potatoes, which are regularly served for the Queen's lunch by the royal chefs along with Dover sole or a roast chicken, while Charles like to eat veg freshly picked from his Highgrove gardens.

Seafood

The royals may privately enjoy a homemade paella or two, but when on official business, seafood is under an outright ban.

According to the BBC, any royal tour could be wrecked by a dodgy mussel or putrid prawn accidentally poisoning a dish, so no chef is allowed to serve a seafood platter. With molluscs estimated to be responsible for around 45% of food poisoning cases, this seems sensible.

However, Meghan is known to be a big fan of seafood and once described sushi as an 'essential' part of her diet - it's hugely popular in California, so she's now never far from a maki roll.

Rare meat

Although medium-rare is generally considered the best way to serve a steak, for the royals, rare meat is out for the same reasons as shellfish - it could cause a nasty bout of food poisoning.

The Queen enjoys venison cooked in oil and butter, with a sauce made from mushrooms, Irish whiskey and cream.

"It was really, really important that we got a really good sear on the steaks and cooked her steak well done," said McGrady.

But while the Queen and the older royals request their beef, game, venison and lamb well done, red meat is of less interest to the younger members of the family.

Kate is known to enjoy vegetarian food more than meat, while Meghan eats largely 'vegan and gluten-free' during the week, and allows herself leeway at weekends - which is just as well, as Harry proposed over a roast chicken.

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Pasta

The Queen does not enjoy pasta, reportedly, and isn't overly keen on rice or piles of potatoes either. She will eat them when out on official duties, but at home she prefers protein and vegetables. It's unlikely the Queen is a secret Keto Bro - she simply prefers light meals when she dines at home.

Kate and William, however, enjoy cooking pasta at home with the children, though Meghan prefers the spiralised courgette version, once admitting that her favourite food is "zucchini bolognese".

She will indulge on the road though - she once told Delish.com, "When I'm travelling, I won't miss an opportunity to try great pasta... I come back from vacation every year with a food baby."

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Tomato sauce

Nobody has ever seen the Queen covered in spatters of bolognese sauce - and there's a reason for that. She won't eat tomato sauce in dishes. Because it can retain so much heat it tends to sizzle, and an unseemly blob could ruin her clothes - or her make-up.

This was revealed prior to the the Queen and Duke of Edinburgh's visit to Rome back in 2000, when chefs were instructed to avoid creating their traditional marinara sauces.

Spicy food

Though Kate loves a curry and likes to season the food she cooks with spices, William is less keen on the hot stuff.

And on royal duty, spicy food is rarely served to any of the royals, due to its reputation for causing indigestion, and the fact that perspiring heavily after a Madras isn't a great look when you're opening a flower show.

...and what they love

The Queen

Crustless tuna sandwiches: Rumour has it she enjoys these for afternoon tea.

Lemon drizzle cake: Supposedly one of her favourites.

Brown eggs: She apparently believes they taste better than white ones

Special K and Earl Grey tea: Her regular breakfast.

Chocolate biscuit cake: This is such a royal favourite, it was served at William and Kate's wedding - and according to McGrady, the Queen never travels without it.

Prince Charles:

He never eats lunch, but has been known to enjoy an egg sandwich.

Cheesy baked eggs are one of his favourite recipes.

Boiled eggs (there's a theme developing).

Risotto, made with lamb and wild mushrooms - ceps and chanterelles - from his own estates.

Kate and William:

They both enjoy vegetarian food, and have let slip that they love sushi (when not on duty).

Kate likes porridge for breakfast, and is said to enjoy a green smoothie with spinach. She's also been reported to love watermelon salads, ceviche, and gazpacho, the chilled Spanish soup.

William is said to love fish and chips- and they both enjoy a barbecue.

Meghan and Harry

Harry used to be a fan of pizza and burgers, but has overhauled his diet now he's in clean-living Montecito.

Meghan enjoys cooking, and has said she makes "Filipino-style chicken adobo in a Crock Pot" and "apple, kale, spinach and ginger" smoothies instead of coffee in the morning.

And of course, all the royals love a roast chicken.

Watch: How to make roast chicken with lemon and garlic