Strategies for Success in Weight Management By: James J. Messina, Ph.D.

1. Glycemic Index & Glycemic LoadGoing for the 3 Increases: Increase in Health, Increase in Happiness & Increase in Energy Strategies for Success in Weight Management By: James J. Messina, Ph.D.

2. Gylcemic Index – GI • A GI value tells you only how rapidly a particular carbohydrate turns into sugar • Not all carbohydrates act the same • Some are quickly broken down in the intestine, causing the blood sugar level to rise rapidly • Such carbohydrates have a high glycemic index (GI).

3. Gylcemic Load - GL • Tells you how much of that carbohydrate is in a serving of a particular food • You need to know both the GI Gylcemic Index and the GL Gylcemic Load understand a food’s effect on blood sugar • Calculating GL allows researchers to better relate carbohydrate intake to its health effects

4. How to Calculate GL • GL is amount of carbohydrate in serving of food multiplied by that food’s GI • Glycemic load of a food is calculated by multiplying glycemic index times the carbohydrate content of food divided by 50g. (GI x CHO content of food / 50 g) • A 12 cup serving of carrots (which has 8 grams of carbohydrate) has a glycemic load of about 10 (8 * 131%, or 1.31 = 10.48).

5. Comparison of GL and GI • GI of a baked potato is 121% (assuming white bread is the standard reference food) • This has earned the potato, which is largely carbohydrate, a place on the “avoid” list in publications and on Web sites promoting the GI approach to food choices

6. Comparison of GL and GI • GI of carrots is high: 131%. But this unfavorable GI rating is based on the blood-sugar effect of eating 50 grams of carbohydrate from carrots — the amount contained in 1 ½ pounds — which few people would consume in one sitting • A serving of carrots doesn’t have much carbohydrate, so its impact on blood sugar is much less than that of a serving of potato

7. Comparison of GL and GI • Avoiding carrots because of their GI ranking would be a big mistake, particularly given all the vitamins and minerals they contain and the low GL of each serving • The GI of potatoes, on the other hand, is not a misleading measure because potatoes are carbohydrate-dense. Their GL is also fairly high

8. Research tells us to lower GL in diet • In American Journal of Clinical Nutrition (March 2001), Nurses’ Health Study researchers used blood samples & food-frequency questionnaire • Used GL measures to assess the impact of carbohydrate consumption on 280 postmenopausal women

9. Research tells us to lower GL in diet • High-GL diets (and, by extension, high GI foods and greater total carbohydrate intake), correlated with lower HDL concentrations and higher triglyceride levels, a marker for heart disease • Strongest association was in overweight women, i.e., those whose body mass index (BMI) was over 25. Increased risk started, on average, at a daily GL of 161

10. How to use the GL in your food plans • Knowing a food’s GL can help you make comparisons that can improve the quality of your carbohydrate choices • Good idea to replace processed and refined-grain carbohydrates, such as those found in many snacks and desserts, with fruits & non-starchy vegetables

11. How to use the GL in your food plans Substitute: • whole grain bread for white bread • wild rice for white rice • beans or lentils for potatoes • Recognize that fruits & non-starchy vegetables as well as whole grains & beans, are rich in nutrients & contain fiber, which slows digestion & moderates blood sugar levels

13. Online References on GI & GL • http://www.ajcn.org/cgi/content/abstract/71/6/1455 • http://archinte.ama-assn.org/issues/v161n4/abs/ioi00112.html • http://www.glycemicindex.com/ • http://www.mendosa.com/gi.htm