You’re absolutely right that breakfast is a very important meal in the day. It sets us up for the day, and as you say it gets our metabolism going after an overnight fast.

With regards to how much you should be eating, there is no set amount which is the ideal. Just eating a little something will be enough to kick-start things for the day. So even if all you can manage is a cereal bar, this is better than nothing.

However, it all depends on how long you’ll have to go until your next meal. If all you can eat is a cereal bar or a piece of fruit, but then you won’t be able to eat again for another 4-5 hours, you’re likely to get very hungry. So it’s often better to try and eat a little more at breakfast time, to see you through until lunch.

What you choose for breakfast can make a difference - there's lots of research which suggests that eating a breakfast that is rich in protein and complex carbohydrates will help to keep you fuller for longer, compared to something like white toast. So opt for poached eggs on wholemeal toast, or wholegrain cereal/ porridge with milk or low fat yogurt. If you can sit down and eat this is better too because research suggests that eating 'properly' helps you to digest food better. Eating on the run is often stressful, and chances are you won't chew properly, or perhaps choose the healthiest option.

We would normally recommend breaking your days calories down as follows:

Breakfast – 20%

Lunch – 30%

Dinner – 30%

Snacks – 20% (this can be broken down into two 10% or just one 20% snack).

It’s best to spread your calories out across the day, and to give your body a steady supply of energy and nutrients. Just as it’s important to eat in the mornings, it’s equally important to continue eating throughout the day to keep your metabolism ticking over. This also helps to avoid any drops in blood sugar or getting too hungry throughout the day.

Now even though you say you have a sedentary job, your body will still be steadily using calorie throughout the day. The system has set you a personal daily calorie target for weight loss, and as long as you don’t go over this amount throughout the day you will be on track to lose weight at the rate you’ve selected.

I hope this helps.