Implement these five changes and you won’t gain weight this summer – in fact, you may even lose as much as 20kg, depending on how bad your current habits are.

Change 1: Go for the fruit, drop the pudding

Summer fruits such as berries, peaches, melons and plums are brimming with protective vitamins, minerals and antioxidants, and they're low in kilojoules and high in fibre. Try eating one of these fruits at each meal to fill you up and boost your immune system.

The difference

lf you eat just five portions of fruit a week (more would be even better) instead of pudding or a 100g bar of chocolate, you won't gain a gram. If you used to eat puddings, cakes and chocolates at least three times a week, your new habit will help you lose up to 5kg in three months.

Change 2: Switch to fat-free dairy products

Research shows eating more fat-free or low-fat dairy products can actually help you lose weight. Using fat-free milk for cereal, coffee and tea means you won't be piling on the kilos this summer.

The difference

lf you replace full-cream milk with skimmed (fat-free) or low-fat (2%) milk, use low-fat yoghurt and cottage cheese instead of the full-cream versions and stick to no more than three portions of dairy a day (three glasses of milk or three small yoghurts or three matchbox-sized portions of cottage cheese) you can lose between 2 and 4kg in three months. How much you lose will depend on whether you choose fat-free or low-fat dairy products.

Change 3: Try non-nutritive sweeteners

Instead of adding two or three teaspoons of sugar to tea and coffee, use artificial or non-nutritive sweeteners. If you have five cups of tea or coffee a day, you'll save between 800 and 1,200kJ.

The difference

You’ll lose between 2 and 3kg in three months.

Change 4: Go slow on the pies, fries and pastries

It’s convenient to snack on pies, pastries, chips and other deep-fried foods, especially if you’re travelling during the summer holidays.

The difference

If you can steer clear of these foods this summer, you have a good chance of not gaining weight. And if you usually eat a pie and packet of chips a day, your new habit will help you lose up to 5kg in three months.

Change 5: Be active

Make a deliberate decision to be more active this summer. Go for brisk walks in your neighbourhood; join a gym; go to dancing, Pilates or yoga classes; or try home workouts. After 10 minutes you'll feel alive and glowing with health.

The difference

If you continue your exercise regime right through summer, you won't gain weight. If you've been a couch potato, you'll lose weight if you start exercising. If you walk briskly for 30 minutes a day, five to six days a week for three months, you'll lose up to 1,5kg in three months. If you add three 30-minute sessions of muscle exercise to your routine three times a week, you can lose 3kg in three months.
, registered dietician, Health24, November 2013