Medical Nutrition Therapy for Diabetes Marion J. Franz, MS, RD, CDE MarionFranz@aol.com
Objectives: Discuss expected outcomes and when to evaluate effectiveness of MNT Review macronutrient questions Select effective nutrition therapy interventions
Is Diabetes Nutrition Therapy Effective? Pre-diabetes outcomes MNT along with physical activity risk of type 2 diabetes by 58%; maintained up to 14 yrs Diabetes MNT goals and outcomes MNT provided by RD: ave. in A1C 1% to 2% (ranging from 0.5 to 2.6%) depending on type, duration, and level of control of db LDL-C by 15-25 mg/dl or by up to 16% SBP and DBP on average by ~5 mmhg Outcomes known by 6 weeks to 3 months AmDbAssoc. Diabetes Care 2012:35(suppl 1):S11; Franz et al. J Am Diet Assoc 2008;108:S52; Van Horn et al. J Am Diet Assoc 2008;108:287; Appel et al. JAMA 2004; 289:2083
United Kingdom Prospective Diabetes Study: A1C (pts newly diagnosed) GLYCOHEMOGLOBIN (HbA1c, %) 9 8 7 6 CONVENTIONAL GROUP INTENSIVE GROUP 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 YEARS UKPDST. Lancet 1998; 352: 837-853
Lessons from the UKPDS Interestingly, the greatest HbA1c reduction was the fall of >2% during the first 3 months with intensive diet and 5% weight loss. Initial glucose response more related to decreased energy intake than to weight loss; decrease in body weight was a secondary response The real problem is the progressive decrease in beta cell function we are now duty-bound to explain this to our patients at the onset and not to castigate them because they failed to diet. R. Holman, Oxford UK. Diabetes Care. 2000;23:1016
Early ACTID (Early Activity in Diabetes) Newly diagnosed type 2 db (n=593) in England, usual care vs intensive nutrition intervention or latter with physical activity program Baseline A1C: 6.7%, 6.6%, 6.7% 6 mo maintained to 12 mo: no improvement in usual care, intervention groups A1C -0.3% (p<0.001), even with use of fewer diabetes drugs Addition of physical activity: no added benefit Andrews et al. Lancet 378:129, 2011
Effectiveness of medical nutrition therapy provided by dietitians in the management of type 2 diabetes: a randomized, controlled clinical trial 8.4 8.2 8.0 7.8 7.6 7.4 7.2 7.0 6.8 A1C 0.9% 4-yr duration of diabetes (A1C 1.7% newly diagnosed) No Educ. 1 RD visit 3 RD visits 6.6 Initial 6 Week 3 Month 6 Month Franz et al. J Am Diet Assoc. 1995;95:1015
Lifestyle Over and Above Drugs in Diabetes (LOADD) Study RCT in 93 pts type 2 db hyperglycemic (A1C>7%) despite optimized drug therapy Intensive MNT according to international nutrition management guidelines vs control Ave duration of db: ~9 yrs Intensive MNT 6 sessions with dietitian A1C 0.4% vs control (P=0.007); comparable to adding new drug to conventional agents; cost-effective Coppell KJ et al. BMJ 2010; 341:c3337
What Nutrition Therapy Interventions Are Effective? A variety of nutrition therapy interventions, such as reduced energy/fat intake, carbohydrate counting, simplified meal plans, healthy food choices, individualized meal planning strategies, exchange lists, insulin-tocarbohydrate ratios, physical activity, and behavioral strategies Type 2 db: reduced energy intake Type 1 db: matching insulin to CHO intake A number of initial individual or group sessions and follow-up encounters were implemented Acad Nutr Diet. www.adaevidencelibrary.com/topic.cfm?=3252
Type 2 Diabetes: A Progressive Disease BG remains normal until insulin deficiency Glucose (mg/dl) 350 300 250 200 150 100 *Postprandial glucose Fasting glucose % Relative to Normal 250 Insulin resistance 200 150 100 At risk for 50 diabetes β-cell dysfunction Insulin level 0-10 -5 0 5 10 15 20 25 30 Years * Post Prandial = 1-2 h ppg Bergenstal RM et al. Management of Type 2 Diabetes in Endocrinology. 4th Edition; Philadelphia, 2001
Type 2 Diabetes: A Progressive Disease Lifestyle Lifestyle Interventions Medical Nutrition Therapy Alone or with Medications Medical Nutrition Therapy Medications Insulin Meds Franz. Am J Lifestyle Med 1:327, 2007
Carbohydrate And Diabetes Most widely held assumption: sugars because they are small molecule are absorbed into the blood stream more rapidly than starches Over 20 studies: when a variety of starches and sugars are selected, the glycemic response is identical, if total amount of carbohydrate is kept constant Sucrose does not increase glycemia more than isocaloric amounts of starch and does not need to be restricted because of concern about aggravating hyperglycemia when substituted for starches
Sucrose In The Diet Of Persons With Diabetes: Just Another Carbohydrate? 12 type 1; 11 type 2; 6 weeks 54% CHO, similar in both diets; all starch or 45 g starch replaced with 45 g of sucrose (18% of calories) No differences: day-long glucose levels, HbA1c, lipids in type 1 and type 2 diabetes; insulin profiles in type 2 Sucrose diet, type 2 Starch diet, type 2 Mean Plasma Glucose* (mmol/l) Peterson DB et al. Diabetologia 1986;29:216
How Important is the Glycemic Index of Food? Diet books define GI as measure of how rapidly a food raises blood glucose after eating Claims made by diet books: Foods that are broken down and absorbed into the blood stream quickly require a lot of insulin High levels of insulin cause blood glucose to drop so low that it triggers new cravings for food. No evidence given for these claims This is NOT the correct definition of the GI Agatston A. The South Beach Diet, 2005
Glycemic Index: The GI Does Not Measure How Rapidly BG Increases! The GI is the relative area under the postprandial glucose curve (AUC) comparing 50 g of digestible carbohydrate from a test food to 50 g of carbohydrate of glucose 170 160 Bread Med GI Bread Low GI Glucose Bread High GI 170 160 Glucose Fruit Juice Fruit 150 150 Glucose mg/dl) 140 130 120 110 100 90 80 0 15 30 45 60 75 90 120 140 130 120 110 100 90 80 Time (min) 0 15 30 45 60 75 90 105 120 No statistical difference in the glucose response curve from different foods Low GI foods do not produce a slower rise in BG nor do they produce an extended, sustained glucose response. Brand-Miller et al. Am J Clin Nutr 2009;89:97
Low GI Meals vs High GI Meals: The Glucose and Insulin Responses Are Parallel to Usual Responses Usual diet GI: 53; low GI: modest improvements in FPG, HbA1c; insulin secretion and sensitivity and body weight unchanged Plasma glucose (A) and insulin (B) before and after 4-wk dietary periods: HGI (Δ, ) and LGI (, ) Low GI, baseline Low GI, 4 wks High GI, baseline High GI, 4 wks Rizkalla et al. Diabetes Care 27:1866, 2004
Problems with the Glycemic Index Based on 50 g CHO portions not actual amounts of CHO in a typical serving; combining foods in a meal changes the GI Considerable variability exists 50 g CHO from bread n=23: GI 78± 73 (CV 94%); second test; n=14: GI 78 ± 39 (CV 50%) Range of GI: 44-132 Not be the best indicator of healthy food choices; soft drinks, candies, sugars and high fat foods have low to moderate GIs; GI by adding or substituting sugars, especially fructose or sugar alcohols, and fat Vega-Lopez. Diabetes Care 30:1412, 2007, Pi-Sunyer. Am J Clin Nutr 87:3, 2008 Franz. Diabetes Care 26:2466, 2003
Glycemic Index (GI) A difficulty of use is its variability Australian potatoes: 87-101 Canadian potatoes: 59-70 US potatoes: 56-77 Boiled rice: 45-112 Bananas: 30-70 Spaghetti: 45-65 All-Bran Australia: 30 All-Bran Canada: 51 Fernandes et al. J Am Diet Assoc 2005;105:557 Food Glucose Cornflakes Sports drink Bread, white Rice, long grain Oatmeal Coke Snickers Bar Banana Spaghetti Milk, skim Kidney beans Apple Premium ice cream Am J Cl Nutr 2002;76:5 GI 99 85+33 78 73+36 71+38 58 58 55 52 47+27 32 28 38 37
Two 1-Year RCT of Low GI Diets: No Differences in A1C Canadian Trial of Carbohydrates in Diabetes 162 subjects with type 2 db randomized to high- CHO/high GI; high-gi/low GI; low-cho/high MUFA No significant differences in A1C, lipids or body weight; low GI small drop within the normal range for CRP Low GI vs ADA dietary education 40 subjects with type 2 db randomized to low-gi or ADA diet Similar reductions in A1C at 6 and 12 mo No association between GI and CRP Wolever et al. Am J Clin Nutr. 2008;87:114; Ma et al. Nutrition. 2008;24:45 Griffith et al. Nutrition. 2008;24:401
GI Summary American Diabetes Association: In general, there is little difference in glycemic control and CVD risk factors between low GI and high GI or other diets. Slight improvement in glycemia from lower GI diets confounded by higher fiber intake. Monitoring total grams of carbohydrate, whether by carbohydrate counting, choices, or experience-based estimation, remains a key strategy in achieving glycemic control Deleted statement that use of the GI may provide a modest additional benefit over that observed when total CHO is considered alone Wheeler et al. Diabetes Care 2012;35:434; American Diabetes Association. Diabetes Care. 2012;35(Suppl 1):S13
GI Summary Academy of Nutrition and Dietetics: GI complicated by differing definitions of high GI or low GI diets or quartiles Conflicting evidence on effectiveness; studies comparing high vs low GI diets report mixed effects on A1C A low glycemic index diet is not recommended for weight loss or weight maintenance as part of a comprehensive weight management program; it has not been shown to be effective in these areas. AmDbAssoc. Diabetes Care. 2009;32(Suppl 1):S23 AmDietAssoc. www.adaevidencelibrary.com/topic.cfm?format_tables=0&cat=3252 AmDietAsspc. Adult Weight Management EBNP. adaevidencelibrary.com/topic.cfm?cat=2798
Carbohydrate: What s Important? Foods containing carbohydrate from fruits, vegetables, whole grains, legumes, and low-fat milk are important sources of vitamins and minerals and provide glucose for the brain Several different macronutrient distributions may lead to improvement in glycemic and/or CVD risk factors ; total energy more important than CHO amount As carbohydrate decreases, total and saturated fats increase Monitoring total intake of carbohydrate is key strategy for achieving glycemic control Negotiate with patients; advise healthful nutrient-dense carbohydrate choices in appropriate amounts and portion sizes ADA. Diabetes Care 2008;31(suppl 1):S61; Wheeler et al. Diabetes Care 35:434-445, 2012; AmDietAssoc. www.adaevidencelibrary.com/topic.cfm?=3252
Dietary Fats and Diabetes In animal and observational studies, higher intakes of total dietary fat, regardless of the fat type, produce greater insulin resistance In clinical trials saturated and trans fats shown to cause insulin resistance, whereas mono- and polyunsaturated and omega-3 fatty acids do not have an adverse effect High fat meals interfere with indexes of insulin signaling which results in a transient increase in insulin resistance Louheranta, 2000; Riccardi, 2000; Denkins, 2002; Lovejoy, 2002; Trichopoulou, 2005
Protein and Diabetes In persons with type 2 diabetes, ingested protein can increase insulin response without increasing plasma glucose concentrations Therefore, protein should not be used to treat acute or to prevent nighttime hypoglycemia In persons with normal renal function, usual protein intake (15-20%) does not need to be changed Although protein has an acute effect on insulin secretion, usual protein intake in longer term studies has minimal effects on glucose, lipids, and insulin American Diabetes Association, Diabetes Care 35(suppl 1): S11, 2012; Acad Nutr Diet. J Am Diet Assoc 110;1852, 2010
Glucose and Insulin Response to 50 g Glucose, 50 g Protein, or Combination in Type 2 Diabetes Glucose response stable with protein alone Glucose peak response the same when protein given with glucose Insulin response double when protein combined with glucose 50 g protein 50 g glucose combined Nuttall et al. Diabetes Care 7:465, 1984
Glucose Appearance and Insulin Response to 50 g Protein or Water in Type 2 Diabetes 50 g protein (very lean beef) or water at 8 am and followed for 8 hrs Protein deaminated, ~20-23 g (changed into glucose in the liver) Amount of glucose appearing in circulation, >2 g Protein ingestion increased insulin levels water protein Gannon et al. J Clin Endocrinol Metab 86:1040, 2001
Protein and DKD Strict control of BG and hypertension is important Protein restriction not warranted in pts with db and microalbuminuria Reducing protein to <1 g/kg/d in pts with db and macroalbuminuria may improve albuminuria somewhat but does not have significant effects on GFR If protein restricted in pts with macroalbuminuria, serum albumin and energy must be monitored and changes in protein and energy made to correct deficits and to prevent potential risk of malnutrition Acad Nutr Diet. EAL 2008; Acad Nutr Diet. EAL 2011; Wheeler et al. Diabetes Care 35:434, 2012;
Prioritizing Nutrition Messages Emphasize blood glucose, lipid, and BP control Nutrition Therapy & Physical Activity Focus on carbohydrate foods, portions, number of servings per meal Encourage physical activity Use food records with blood glucose monitoring data
What s the best nutrition therapy intervention for diabetes?
In An Ideal World People with type 2 diabetes: Lose 5% to 10% of baseline weight Eat a nutrient dense eating pattern in appropriate portion sizes Participate in 150 min/wk of regular physical activity People with type 1 diabetes: Count carbohydrates Adjust insulin based on insulin-to-cho ratios Use correction factors
In the Real World Facilitate behavior changes that individuals are willing and able to make based on proven lifestyle interventions A variety of nutrition therapy interventions can be implemented But lifestyle interventions for diabetes are effective!