Dietitian Susie Burrell has revealed why the secret to lasting weight loss is a light dinner - and why you should never eat later than 8pm.

The expert, from Sydney, said that while, for many of us, dinner is the largest meal of the day, in fact we should be eating fewer calories at this time to give our bodies a break.

Susie recommends you eat no more than 300 or 400 calories at 6pm, and said you should never eat later than 8pm.

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Dietitian Susie Burrell (pictured) has revealed why the secret to lasting weight loss is a light dinner - and why you should never eat later than 8pm

Between snacks, alcohol and a heavy carb-laden dinner, it's easy for the calories to spiral once you get home - but Susie said you should keep dinner (pictured) to 400 calories or less

'It is not uncommon to see clients who consume more than 1,000 calories after 6pm each day - so is it any wonder so many of us find it hard to fend off the kilos?,' she wrote on her blog.

Between snacks, alcohol and a heavy carb-laden dinner, it's easy for the calories to spiral once you get home and hit the sofa.

One of the 'most powerful' steps you can take towards losing weight, Susie said, is keeping your evening meal light.

'Not only does a light evening meal mean that you are more likely to wake up the next day and feel hungry for a breakfast meal, but eating light at night will help you to sleep better and support weight loss, if that is your goal,' she explained.

Susie said that meals like the frittata can carry as few as 240 calories, when you make them with eggs, grated vegetables and not too much cheese (stock image)

If you are looking to keep your dinner under 400 calories, Susie said the trick is to focus your dinner around vegetables and salad, while keeping your protein servings small.

A palm-sized piece of meat, chicken or fish will suffice, she said, and if you like wine, carbs and dessert, it's best to make a choice between one or the other if you want to stay slim.

'Most importantly, give yourself an eating cut off time - ideally we need at least 12 hours without food overnight, which means switching off the kitchen lights at the latest,' Susie said.

If you absolutely have to eat something after then, then try something low calorie - like berries or herbal tea or low sugar hot chocolate.

Susie's ideal dinner choices include naked burgers, which she serves with salad, prawn stir fry, turkey meatballs, grilled fish and roasted vegetables and vegetable frittata

Susie's ideal dinner choices include naked burgers, which she serves with salad, or prawn stir fry, turkey meatballs, grilled fish and roasted vegetables or vegetable frittata.

She said that meals like the frittata can carry as few as 240 calories, when you make them with eggs, grated vegetables and go easy on the cheese.

'While tuna and salmon are on the higher calorie side thanks to their rich omega 3 contents, if you stick to white fish and team it with a bucket load of low carb veggies such as zucchini, eggplant, capsicum, onion and pumpkin, you will strike a perfect balance between low cal and low carb,' Susie said.