I switched to GL straight from TFR. I felt this made it easy for me as all the bad habits had been broken on TFR plus the detoxing headaches etc were also out of the way.
GL is based on keeping your blood sugars or insulin levels fairly level throughout the day. It is slumps in these levels that will make us hungry and lead to overeating. Certain food will also make these levels peak quickly and then slump just as quickly. The foods that do this include high carb foods, high sugars etc.
To keep blood sugars level it is best to eat foods that are more slowly digested by the body thereby leaving us feel fuller for longer.
Some GL diets use a traffic light system with red = high GL amber= medium and green = low gl. Rick Gallop uses this system.
Others calculate the GL of foods recommending a total intake of 45gl per day for weightloss. Patrick Holford does this one.
Personally, I read loads on the subject and then adapted it to suit myself.
I stick to an overall calorie intake, 1200, for the day, moreso to keep portion sizes in check.
I choose low GL foods
I drastically limit bread/potato/pasta/rice.
I eat leafy green veg and berried fruit mostly.
I have rye crackers or oatcake when I feel I need a bread.
I have lentils/beans/quinoa instead of rice/pasta or potato.
I also stick to an 80/20 rule. I try to be good 80% of the time.
Click on the link in my signature and this will take you to the GL forum on minimins.
Ask any questions you like, I'm happy to give my tuppence worth!!
I should also say, I never feel deprived and rarely feel peckish. I think it is fab!!!!
GI was around first and it is based on the calculation of the effect of a particular food on your blood sugars. GL takes this to the next level by measuring the effect of a portion of a food on your blood sugar. Melon is an example that is used to show what they mean. No one sits and eats a whole melon. Now the GI of melon is high but if you look at the effect of a portion of melon it is then low so it gets classed as low GL as opposed to high GI.
Whether you follow GI or GL it does not really matter imo.