From looking at the charts it looks like milk is much better. It has a good balance of protein fat and carbs.
However post workout we need an insulin spike and lots of protein. Yoghurt contains more protein, and more carbs, I.e. more of what we want.
The sugar in milk is lactose, which is a disaccharide derived from the condensation of galactose and glucose. This requires the intestinal villi to secrete the enzyme called lactase in order to break down the lactose into the simple sugars glucose and galactose, which can in turn be absorbed. In most mammals the production of lactase gradually decreases with maturity due to a lack of constant consumption. So the older you get, the harder it is for your body to deal with milk.
Yoghurt is fermented milk. Bacteria uses the lactose in milk to produce lactic acid, which acts on milk protein to give yoghurt its texture and different taste. Most of the lactose in milk is converted to lactic acid by the bacterial culture, this process also creates lactase, meaning that the body has less lactase to make itself during the absorption process.
Glycemic Index in Milk & Yogurt
The G.I. list also shows the carb content for each item as this is related somewhat to Glycemic load for the G.I. diet. However it does not necessarily mean that a food with a high carbohydrate content will automatically mean a high G.I. score.
All foods on the G.I table is based on 100g of product. The portion size doesn't change the Glycemic Index value, but it does count towards the quantity of sugar (carbs) for the item; the bigger the portion the more sugar you would be consuming.
This standard portion size simply enables you to make a sugar comparison with other products in the same group, and the different foods listed on other G.I. tables. This means you can see which foods are high or low in carbohydrate content.
Yoghurt contains 20% more protein than milk
Yoghurt is easier to digest than milk
Yoghurt & milk both spike insulin fast, but milk is good because it does the job with less carbs.
(The G.I. index of natural yoghurt is about the same as milk)
Yoghurt contains gut healing bacteria
Yoghurt is good for internal fungal infections
I'm going to go for yoghurt over milk from now on because of the protein and digestion factors.
Milk is harder for the body to process so how can it have the same glycemic index as yoghurt?