Public Health England’s new calorie guidelines – 400kcal for breakfast, 600kcal each for lunch and dinner – put me right off my 474kcal bowl of muesli this morning. Especially when I found out I could have had a butter croissant, which has a mere 309kcal.

Dr Frankie Phillips, a dietician and spokeswoman for the British Dietetic Association, cautions against going too far down this road. “Having some guidance is useful, but calorie content isn’t the whole story – you could easily stay within the limits and have a lot of crisps, chocolates and fizzy drinks, and miss out on essential nutrients. We need to make sure those aren’t empty calories.”

She recommends filling up with high-fibre foods and making sure that vegetables are a key player, “not just a condiment”. As someone who regularly eats as much leafy green stuff and roasted veg as I can physically fit in on a fast day as part of the 5:2 diet, I can confirm vegetables do indeed fill you up surprisingly well.

You could start with an apple, a pot of Greek yoghurt and a spoonful of honey (336kcal), or even a Greggs bacon roll, which comes in at a svelte 337kcal. Breakfast, then, as long as you avoid buckets of milky latte (200kcal for a medium Costa cup) is simple enough.

Lunch is even easier for the three-quarters of British workers who buy it: most shops display calorie counts to shame you into replacing that cheese and ham sub (534kcal at Tesco) with a Healthy Living tuna and cucumber sandwich (268kcal), leaving you plenty of room for an orange (62kcal) and even a bag of cheese and onion crisps (169kcal). Nutritionally, however, you would be better off going for a big salad (Waitrose’s tuna nicoise is 297kcal) or a chunky soup: Sainsbury’s chicken and vegetable broth is only 119kcal a serving, although I would be tempted to finish the whole pot.

As for dinner at home, a portion of M&S lasagne exceeds the 600kcal guidelines, but you could make your own from the recipe on BBC Good Food website at 580kcal. Or, if you’ve already squandered your snack allowance, you would be well advised to try their spring vegetable noodles (339kcal) if you fancy a glass of wine (160kcal), let alone a square of dark chocolate (17kcal). Frankly, after a hard day peering at labels, you may need both.