Do sugar and salt hold your fat in your body?

How does blood sugar level respond to ingestion of sugar?

• I have heard that when one ingests sugar in concentrated form like chocolate (as opposed to in the form of starch, which breaks down more slowly), the body overshoots in its insulin production so that after 15-20 minutes (recalling from memory, may be slightly off) your blood sugar level is lower than the one you started out with - a situation which lasts for two hours until your blood sugar level is restored. So, students who are about to take long exams are advised not to take sugar for boost until about the last half hour of their exam. This question is intended to understand if that's true. Two dose-response curves - one for the amount of sugar in a typical chocolate bar, one for that in a typical lunch or an unripe banana after broken down - for a healthy individual with no abnormalities in insulin production or secretion should suffice. But if all you have is verbal knowledge, don't hold it back :)

• Answer:

  What you're asking about is termed glycemic response. It's related to the glycemic index of different foods. Glycemic index (GI) is a way of quanitfying the effect of various foods on one's blood glucose. Essentially, GI was quantified for various foods by measuring the response in blood glucose to different foods as a percentage of the blood glucose rise for a pre-determined amount of pure glucose (e.g. does 50 grams of white bread cause the same rise in blood glucose as 50 grams of pure glucose). This is depicted graphically below in a figure excerpted directly from Jenkins, et al. (1981): So the simple way to think about this is that foods with a high glycemic index cause a sharp rise in blood glucose while foods with a low glycemic index cause a shallower increase in blood glucose. A better way of looking at this is actually glycemic load, which is glycemic index modified to account for a standard serving of given foods. Several websites publish this information: http://www.health.harvard.edu/newsweek/Glycemic_index_and_glycemic_load_for_100_foods.htm. Feel free to comment  / PM with any further questions. EDIT: In response to your comments, I've added this figure to clarify the response of insulin to increased blood sugar: (excerpted directly from source #2) [2] Citations: 1:Jenkins DJ, Wolever TM, Taylor RH, et al. (March 1981). http://www.ajcn.org/cgi/pmidlookup?view=long&pmid=6259925. Am. J. Clin. Nutr. 34 (3): 362–6.http://en.wikipedia.org/wiki/PubMed_Identifier http://www.ncbi.nlm.nih.gov/pubmed/6259925. 2: Harvey, RA, Ferrier DR.  Biochemistry: Lippincott's Illustrated Reviews. 5th ed. Philadelphia: Lippincott Williams & Wilkins, 2011