A hundred grams of pizza is likely to harbour between 250 and 300 calories, and the same weight in chips (French fries, if you insist) over 300. A large hot dog will add nearly 200 more to the count, and the fizzy drink this is washed down with, another 100 to 200.

Of course, the more sensible option for parents who are big fans of children’s parties but don’t want to get even bigger, is to stick to the adult fare – if there’s any on offer. Then the maths is a little less scary, though it’s often the dips, condiments and other accompaniments you have to watch out for.

Mini samosas and mini Thai fish cakes both usually contain around 70 calories each, but the sweet chilli sauce that comes with the latter is likely to contain as much sugar as an equivalent quantity of jam.

Chicken is an excellent source of lean protein, but again the 20 or so calories on a mini satay stick can be greatly inflated by too much of the peanut sauce sitting next to it.

Good guacamole can be made almost entirely from vegetables but you’re likely to want to use potato chips to get it out of the bowl. Thirty grams of potato chips is going to add around another 160 to the count, and three or four cheese cubes, a further 80.

The roughly 50 calories in a mini smoked salmon and cream cheese bagel adds up to a decent balance between enjoyment and health, and the raw vegetables on a plate of crudités are going to do you nothing but good – as long as you don’t go mad with the dip that will be probably be proffered with them.

However, the benefits of the vegetables in a small vegetable quiche can be rapidly outweighed by the 80 to 120 calories in the butter, milk and cheese it also contains.

When it comes to liquids, a large glass – that’s 250ml – of red wine will tip the scales at around 210 calories, while a can of beer comes in at just over 150.

And it’s a good idea to first check whether the nuts are raw (good) or coated with oil, salt or sugar (not so), before you start shovelling them back with your drink.

You can also use a little personal game management, to strike some sort of health / fun balance.

Probably the most important calorie-dodging tactic is to make sure you take on plenty of ballast, both in the form of solids and liquids, before the event. The idea is to avoid arriving so dehydrated you want to start swigging wine, or the children’s fizzy drinks, straight from the bottle, or hungry enough to eat the paper plates.

Getting a young family ready for any trip can mean the adults, after sorting out all their children’s needs, forget to look after themselves. Try to ensure you eat a solid breakfast or lunch, and have drunk plenty of water, before setting out.

Positioning can give will power a helping hand, too. Put a bit of distance between yourself and the buffet so you have to make a conscious decision to get more food and you can’t unthinkingly nibble.

The truth is, though, if the rest of the time you’re watching what you eat and getting regular exercise, over-indulging on a few occasions probably isn’t going to do you much harm.

And, remember, you’re also likely to have burned up plenty of calories chasing the little rascals around the bouncy castle, and then carrying them home asleep.