Health Effects of Excess Sugar

The past few days, all Ive been doing is binging on pure sugar. And that's all I've eaten....

Someone please tell me the detrimental effects of consuming over 300g of sugar each day! And not natural sugars either (sugar in chocolate, muffins, donuts, chocolate milk, jam, etc). Its a regular thing for me to eat a whole jar of jam at once as part of a sugar binge.

A few days of over-indulging on sugar won't harm you especially.  Your teeth are probably most at risk.... good brushing needed to prevent cavities.  Excess sugar in the body also leads to excess insulin production.... this is believed to cause certain problems over the long-term rather than a few days.  One immediate, visible effect of excess insulin is that some people break out in spots!

There's nothing intrinsically wrong with the foods you describe but they aren't supplying you with much else beyond a lot of instant-access energy.  Sugar energy is absorbed quickly, used up quickly and could leave you feeling quite irritable, lethargic and hungry as a result...... which tends to lead to a need to eat more sugar. 

I note from another post that you're underweight....  This makes sense.  Starved bodies will look for quick-fix energy every time.  Aim for 2500-3000 cals a day so that you gain to a healthy BMI (20 minimum)  If you get more energy from other, slower-burn foods.... wholegrains, lean meat/fish, beans/pulses, vegetables, fresh fruit, fats/oils, dairy products.... then you might feel healthier. 

Starting with breakfast..... make yourself something like eggs and peanut butter with wholegrain toast, a glass of milk and a banana.  The combination of protein, fat and fibre should be a little more satisfying and you may find you don't need quite so much sugar.

In addition to the advice above, my only 2 cents are that if you really love jam, you should try and add it to something consistent. Eat it on toast or crackers, on a banana or in cottage cheese, and you will get the benefits of added nutrition without having to give up the food you love.

Also, you will probably be eating a lot less jam if you eat a slice of bread with every couple tablespoons. :)