The eat-all-day diet

'Many diets involve creating complicated meals with unusual ingredients that most people don't have the time to prepare,' says Simon Lovell, author of the new and improved Lunch Box Diet (HarperCollins, £12.99), which our eat-all-day plan is based on.

'They're hard to stick to because they're so restrictive, stressful and boring. When you starve yourself, you end up lowering your metabolism as your body goes into preservation mode and stores whatever you feed it,' says Simon.

'Eating little and often means your body is more likely to burn fat instead of storing it.'

At first, introduce the diet into your life three days a week, building up to every working day. If you stick to it at weekends, too, you can lose up to 3lb a week.

So what are you waiting for? Dig out a lunch box and start tucking in...

SO WHAT'S FOR BREAKFAST AND DINNER?

If you're new to the eat-all-day diet, start by eating whatever you'd normally have for breakfast or dinner, and gradually build up to a healthier meal.

Brilliant breakfasts

• EGGS Boil or poach - don't fry.

• CEREAL Look for a fibre content of more than 5g per serving and no added salt, sugar or flavourings.

• SMOOTHIES Blitz your own using fresh fruit. Delicious dinners Plan your week's meals in advance. Keep an eye on portions - a serving of meat should be about 80g (the size of a deck of cards).

Delicious dinners

Plan your week's meals in advance. Keep an eye on portions - a serving of meat should be about 80g (the size of a deck of cards).

• CHICKEN Grilled with roasted veg

• LAMB Stewed, plus steamed veg

• FISH Salmon with roasted peppers and couscous

VEG Homemade lasagne

What to put in your box

GROUP A VEGETABLES - 45% TO 60% OF YOUR BOX

The key here is colour - choose a rainbow of vegetables. Use fresh and organic wherever you can and steam, grill, oven bake or microwave any veg that needs to be cooked. Pick five of the following and aim for one from every group:

• Plant sources Tofu, chickpeas, beans, lentils, seeds, nuts

• Red Beetroot, peppers, radishes, tomatoes, watermelon

• Orange and yellow Carrots, pumpkins, squash, sweetcorn, sweet potatoes

• Green Artichokes, asparagus, broccoli,celery, peas, cucumber, green beans, green leaves

• White Cauliflower, leeks, mushrooms, parsnips, shallots and onions

• Indigo & violet Aubergines, red cabbage, turnips

GROUP B LEAN PROTEIN - 15% TO 30% OF YOUR BOX

This bit of the box is what gives you staying power and helps you feel satisfied for longer. Pick one of the following protein sources each day:

• Beef Sirloin, rump steak, topside, silverside

• Lamb Shoulder, rack or cutlets

• Fish Oily: salmon, sardines, herring, mackerel, trout, tuna. White: sole, coley, pollack, black bass, sea bream

• Shellfish Prawns, shrimp, crab, lobster, mussels, cockles, scallops, oysters

• Poultry Chicken or turkey breast

• Pork Pork and lean cuts of ham

• Eggs

GROUP C DRESSING - 10% OF YOUR BOX

Sprinkling a dressing on your box will bring it to life. Make your own or buy one, but check the labels for added sugar. And remember, a little goes a long way, especially as your veggies will be steeped all day in whatever you add.

SAUCY SUGGESTIONS

● Cheese - grated

● Guacamole

● Houmous

● Oils - olive or nut (just a splash)

● Olives and capers

● Pesto

● Salsa

● Tapenade

● Tzatziki

● Vinegar - plain, fruit-flavoured, cider or wine

● Chinese-style dressings - try rice vinegar, sesame oil or soy sauce

GROUP D ACTIVE CARBS - UP TO 30% OF YOUR BOX

If you sit at a desk all day, leave carbs out of your box. Chances are, if you're used to eating three times a day, you'll still notice a significant improvement in your energy as your blood sugar levels stabilise. But if you are diabetic, very active or just feel sluggish, add an active carb from the following:

● Barley

● Brown or wild rice

● Oatcakes

● Quinoa

● Rye bread or crackers

● Wholegrain bread

● Wholegrain couscous