Looking at how much you eat a person would think that you should be loosing the weight you want to loose quickly, but this might come as a surprise.  You are eating too little to loose weight. 

When we eat too little we starve our bodies and our metabolism slows down so that the body can survive on less.  When we eat regular balanced meals the metabolism will speed up as the body knows that it is getting enough food on a regular basis and does not have to store energy or use less.  If small meals are eaten regularly the body is never starved and a person is less inclined to over eat, because blood-glucose levels stay more stable. 

The reason why you “pick up a kilogram” if you have something small like a sweet is that the body is keeping that energy for in case you are going to starve it again.

A well balanced breakfast that includes a starch such as a high fiber breakfast cereal and fat free milk or yoghurt, will provide enough energy to sustain you up to lunch.  To keep blood-glucose as even as possible and optimise fat loss, when choosing carbohydrates, rather choose foods that have a low Glycaemic Index and is high in fiber.

Trying to loose weight without doing regular exercise will lead to muscle loss, since the body finds it easier to turn muscle into energy, than to burn stored body fat.  Exercise increases lean body mass, which in turn increases metabolism.

Lastly, drinking 6-8 glasses of water per day will help rid the body of waste products and toxins; this will help to speed up the metabolism.

In short: to loose weight we need to stimulate the metabolism so that the body burns more energy.  To do this we need to eat regular low fat, high fiber meals, do enough exercise and drink enough water.