Presentation on theme: "Melita Schuster, DO Mike LaFontaine, PhD Marian University College of Osteopathic Medicine Deconstructing Diets."— Presentation transcript:
Melita Schuster, DO Mike LaFontaine, PhD Marian University College of Osteopathic Medicine Deconstructing Diets
Why do we care about diet? Obesity is a risk factor in most of the leading causes of death in the US. Diet and Exercise influence many of these as well. Top Ten Causes of Death in the US Heart Disease Cancer Chronic Respiratory Diseases Accident Alzheimer’s Disease Diabetes Kidney Disorders Influenza and Pneumonia Suicide From CDC
Obesity in the United States States with greater than 10% obesity First year with data from all 50 states -50 states with greater than 10% obesity -No state with greater than 20% obesity Only Colorado with less than 20% obesity Last year for Colorado under 20%
ENERGY METABOLITES AND BIOMOLECULAR BUILDING BLOCKS. Carbohydrates Lipids Proteins/Amino Acid VITAMINS AND MINERALS Variety of uses, but NOT an energy source. Nutritional Components
Carbohydrates in Diet Complex carbohydrates require digestion, slowly enter circulation. Simple sugars are rapidly absorbed. Excess blood glucose increases fat storage, increased glycosylation of LDLs. Simple Sugar Complex Carbohydrate
Dietary Proteins and Amino Acids Typically require 0.8g/kg/day Protein toxicity can occur with as little as 2g/kg/day in individuals with pre-existing renal disease. Animal derived proteins typically have sufficient spectrum of amino acid content. Grains lack lysine, legumes low in methionine.
Lipids Diverse category that includes cholesterol, phosphoglycerides, triglycerides, sphingolipids. Source of fatty acids, omega-3 and omega-6 are essential dietary components.
Dietary Fats and Prostaglandins, Thromboxanes, and Leukotrienes. Dietary intake influences precursors for synthesis of prostaglandins, thromboxanes, and leukotrienes.
Hormonal Role in Hunger Cholecystokinin Short-term satiety signal released from I-cells. Leptin Satiety signal released from adipose tissue. Ghrelin First identified circulating hunger-inducing hormone. Released from fundus and pancreatic epsilon cells. NPY neuron G I L NPY
What Diet Is Best? Weight Watchers Zone Atkins Jenny Craig Flexitarian LEARN Volumetrics Mediterranean diet Anti-Inflammatory diet TLC diet Engine 2 Diet Biggest Loser diet Eco-Atkins Flat Belly diet Spark Solution diet South Beach diet Macrobiotic Raw Food diet Slimfast Acid Alkaline diet Nutrisystem New Glucose Revolution Paleo Dukan DASH Mayo Clinic diet Ornish Vegetarian Vegan
The Debate What type of diet is most effective for losing weight? Those that emphasize protein? Those that emphasize carbohydrates? Those that emphasize fats? Variable studies: some show benefit with low-CHO, high-protein diets over high-CHO, low-fat diets, but other studies do not show this effect. Other studies have shown benefit with vegetarian (high CHO, low fat) over conventional high CHO, low fat diet Low fat vs. moderate fat: mixed reviews
Let’s Look at Some Studies
ARTICLE: “Comparison of the Atkins, Zone, Ornish, and LEARN Diets for Change in Weight and Related Risk Factors Among Overweight Premenopausal Women: The A to Z Weight Loss Study: A Randomized Trial” JAMA 2007 Outcomes: Weight loss Lipid profile Body fat Waist-hip ratio Fasting insulin and glucose levels Blood pressure JAMA. 2007;297(9): doi: /jama
RESULTS Atkins: lost more weight and experienced more favorable overall metabolic effects at 12 months. Weight loss: (at 12 months) Atkins: 4.7kg LEARN 2.6kg Ornish 2.2kg Zone: 1.6kg
Mean Changes in Outcomes at 12 Months AtkinsZoneLEARNOrnishP value Body mass Body fat % Waist/hip ratio o LDL-C HDL-C TG Non HDLc Insulin Glucose Systolic BP <.001 Diastolic BP
Very Low CHO diet vs. Calorie Restricted Low Fat diet 2003 study on very low CHO diet and calorie restricted low fat diet: (53 patients) Very low CHO: lost more weight and body fat than the low fat diet. Over 6 months: no deleterious effects noted for CV risks Blood pressure, Glucose, lipids, Insulin : same changes in both groups (J Clin Endocrinol Metab 88:1617–1623, 2003)
2005: Comparison Atkins, Ornish, Weight Watchers, Zone 2005 JAMA: (161#) Weight loss: Atkins: 2.1kg Zone: 3.2kg Weight Watchers: 3.3kg Ornish 3.3kg Each diet decreased LDL/HDL ratio by 10%. No effect on BP and glucose JAMA. 2005;293(1): doi: /jama
2006: Low CHO vs. Low fat on Weight Loss and CV Risks 447 people At 6 months: Low CHO lost more weight, but at 12 months, there was no difference in weight loss between the 2 groups No change in BP Low CHO: TG and HDL improved Low Fat: total cholesterol and LDL improved Arch Intern Med. 2006;166(3): doi: /archinte
Conclusion: “Low-carbohydrate, non–energy-restricted diets appear to be at least as effective as low-fat, energy- restricted diets in inducing weight loss for up to 1 year. However, potential favorable changes in triglyceride and high-density lipoprotein cholesterol values should be weighed against potential unfavorable changes in low-density lipoprotein cholesterol values when low-carbohydrate diets to induce weight loss are considered.” Arch Intern Med. 2006;166(3): doi: /archinte
“Effect of an energy- restricted, high- protein, low-fat diet relative to a conventional high- carbohydrate, low- fat diet on weight loss, body composition, nutritional status, and markers of cardiovascular health in obese women.” 2005 study Weight loss: both diets: 7.3# in 12 weeks High protein diet: Decreased TG Decreased body fat Both diets improved LDL, HDL, glucose, insulin, C-reactive protein Conclusion: “ An energy-restricted, high-protein, low- fat diet provides nutritional and metabolic benefits that are equal to and sometimes greater than those observed with a high-carbohydrate diet.” Am J Clin Nutr.Am J Clin Nutr Jun;81(6):
“A Dietary Quality Comparison of Popular Weight-Loss Plans” Compared: New Glucose Revolution: low glycemic index Weight Watchers: point system based on energy, fat, fiber Atkins: low CHO, high fat diet (4 phases) South Beach: 3 phases (recommends certain CHO and fats) Zone: reduced CHO, low energy diet 40% CHO, 30%protein, 30% fat Ornish: <10% from fat. All animal products are excluded 2005 US Dept of Agriculture Food Guide Pyramid Dietary quality was measured by the Alternate Healthy Eating Index (AHEI) Purpose of study: compared dietary quality as well as other nutrients associated with CVD J Am Diet Assoc. Oct. 2007: 107(10):
Dietary quality is defined as the degree to which a diet reduces risk for CVD disease Obesity is associated with an increased risk for CV disease Given that obesity is a risk factor for CVD, a weight loss plan that is optimal will not only facilitate weight loss, but will reduce CVD reduction.
AHEI Was developed to improve the Health Eating Index AHEI is twice as strong a predictor of CVD over the HEI Nine components: Fruit Vegetables Nuts and soy Ratio of white to red meat Ceral fiber Trans fat Ratio of polyunsaturated fat to saturated fat Alcohol Duration of multivitamin use
Several nutrients important for CVD risk reduction were also analyzed: CHO Fat Protein Percent energy from saturated and monounsaturated fat N-3 fatty acids Total fiber Sodium
AHEI Scores DietOptimal: 70 Ornish64.6 Weight Watchers- high CHO57.4 New Glucose Revolution57.2 South Beach/Phase Zone Food Guide Pyramid48.7 Weight Watchers high protein47.3 Atkins 100g CHO46 South Beach/Phase Atkin 45g CHO42.3
HEI vs. AHEI HEI: created at first to identify dietary factors associated with reduced CVD risk and to evaluate a plan’s potential to improve lipid levels and obesity. It did not predict CVD mortality however because it did not distinguish between the different types of CHO and fats AHEI: found to be twice as good at predicting CVD How is this helpful? The AHEI may help to establish long term plans for weight loss and thus affecting CVD risks as well. Most plans can lose weight in the short term, but it’s the long term effects over time that matters.
OmniHeart Study Compared 3 diets: Carbohydrate-rich diet, similar to the DASH diet; Diet rich in protein, approximately half from plant sources; Diet rich in unsaturated fat, predominantly monounsaturated fat. Goal: all 3 diets are low in saturated fat. The study looked at blood pressure and serum lipids
OmniHeart Study Compared with CHO diet: Protein diet: Decreased systolic BP 1.4mmHg without HTN, and 3.5 with HTN Decreased LDL 3.3mg/dL, Decreased HDL 1.3 md/dL Decreased TG 15.7mg/dL Unsaturated fat diet: Decreased systolic BP 1.3mmg without HTN, 2.9 with HTN No change in LDL Increased HDL 1.1mg/dL Decreased TG 9.6mg/dL Conclusion: partial substitution of CHO with either protein or a monounsaturated fat diet can further lower BP, improve lipids and decrease CV risk. JAMA. 2005;294(19): doi: /jama
Lyon Heart Study 300 subjects Study stopped early because of benefits on heart disease 50-70% lower risk of recurrent heart disease This is a secondary prevention trial Circulation. 2001;103:
PREDIMED Study Primary Prevention of Cardiovascular Disease with a Mediterranean Diet Studied efficacy of 2 Mediterranean diets: One supplemented with extra virgin olive oil and the other supplemented with nuts. Compared with low fat diet Conclusion: the results supported a Mediterranean diet for primary prevention of cardiovascular disease N Engl J Med 2013; 368: April 4, 2013DOI: /NEJMoa April 4, 2013
Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease American Journal of Clinical Nutrition: published Jan. 10, 2010: provided a lot of controversy about saturated fat Meta-analysis of 21 studies Conclusion: “A meta-analysis of prospective epidemiologic studies showed that there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD. More data are needed to elucidate whether CVD risks are likely to be influenced by the specific nutrients used to replace saturated fat.”
“ Comparison of Weight-Loss Diets with Different Compositions of Fat, Protein and Carbohydrates ” 811 overweight subjects Assigned to 4 diets Study : 2 years Primary outcome: change in body weight after 2 years comparing different diets N Engl J Med 2009: 360: , Feb. 26, 2009
Diets Studied: DietFatProteinCHO 1: low fat, average protein 20%15%65% 2: low fat, high protein 20%25%55% 3: high-fat, average protein 40%15%45% 4: high fat, high protein 40%25%35%
BMI years old -2x2 factorial design: 2 diets low-fat, 2 diets high-fat, and 2 diets were average protein, and 2 were high protein -<8% saturated fat, 20 g fiber/day, 150mg cholesterol per 1000 kcal Diets were randomized, daily meal plans provided -deficit of 750 kcal per day from baseline Group sessions/individual sessions Physical activity goal: 90 minutes moderate exercise per week Body weight and waist circumference measures
Primary outcome: change in body weight over 2 year period Secondary outcome: change in waist circumference Note: Most of the weight loss occurred in first 6 months (6.5kg) After 12 months, all groups on average, slowly regained body weight 23% continued to lose weight from 6 months to 2 years At 2 years: 31-37% had lost at least 5% of initial body weight 14-15% had lost at least 10% of their initial weight 2-4% lost 20kg or more
All diets reduced risk factors for CV disease and diabetes at 6 months and 2 years The 2 low fat diets and highest CHO diet decreased LDL more than the high fat diet or lowest CHO diet Lowest CHO diet increased HDL more than High CHO diet All diets decreased TG similarly Serum insulin levels: all diets except high CHO BP decreased 1-2mmHg in all diets Metabolic syndrome: present in 32% at start and after 2 years 19-22% overall
HDL: increased in the lowest CHO diet than in highest CHO diet Attendance at group sessions strongly predicted weight loss at 2 years Principal finding: Diets were equally successful in promoting weight loss that was clinically meaningful Adherence to the diets was the most challenging Conclusion: “Reduced calorie diets result in clinically meaningful weight loss regardless of which macronutrients they emphasize.”
Mean Change in Body Weight and Waist Circumference from Baseline to 2 Years According to Dietary Macronutrient Content. Sacks FM et al. N Engl J Med 2009;360:
So what does this mean? When looking at the studies, there is not clear evidence that one diet prevails over another for weight loss. There are strong studies regarding the Mediterranean diet in both primary and secondary prevention in cardiovascular disease.
So what advice do I give to patients? There are lots of “fad” diets out there. Become familiar with the popular diets and be ready to discuss them with your patient. The key is finding something that the patient will adhere to and stay with DIET is a 4 letter word and is not allowed! Rather, “lifestyle changes” is the goal!
US News and World Report: Best Diets Best Diets Overall Best Weight Loss Best Diabetes Diets Best Heart Healthy Diets Best Commercial Diet Plans Best Diets for Healthy Eating Easiest Diets to Follow Best Plant Based Diets
USDA Food Guide Pyramid The original pyramid did not point the way to healthy eating In 2005 it was replaced with My Pyramid: the old pyramid turned on it’s side, but it was vague and confusing June 2011: replaced it with My Plate The plate still falls short on the nutrition advice they need to choose healthy diets.
Healthy Eating Pyramid/Healthy Eating Plate Developed by Harvard School of Public Health, updated in 2008 Developed the Healthy Eating Plate to replace My Plate (2011) Based on best available scientific evident about links between diet and health The pyramid has a foundation of daily exercise and weight control. Simple rule of energy balance: Weight change = calories in – calories out
Problems Nutrition advice by law must be considered for revision every 5 years Government seeks a panel of experts The panelists are subject to intense lobbying from National Dairy Council, United Fresh Fruit and Vegetable Association, the Soft Drink Assn, the American Meat Institute, the National Cattlemen’s Beef Assn, the Salt Institute, and the Wheat Foods Council. The guidelines can determine what food products Americans buy and determine how billions of dollars are spent.
“Can We Say What Diet is Best for Health?” Drs. Katz and Dr. Meller: Ann Rev Public Health : There have been no long term studies comparing diets The weight of evidence supports a theme of healthful eating, with variations among this theme. Compared: Low CHO, Low fat, Low glycemic, Mediterranean, Mixed balanced, paleolithic, vegan, other
If diet denotes a set of rigid principles, then, no, we can’t say what diet is best. However, if by diet, we mean a more general dietary pattern, then yes, we can say what diet is best: Evidence supports: Diets consisting of minimally processed foods Diet of foods mostly direct from nature Diets with exaggerated emphasis on any one nutrient or food is ill advised Diets need to consist of a complete dietary pattern
New Evidence: March 2014 “Fruit and vegetable consumption and all-cause, cancer and CVD mortality: analysis of Health Survey for England data” J Epidemiol Community Health doi: /jech An inverse association exists between fruit and vegetable consumption and mortality Benefits seen in up to 7+ portions daily
Fruit and vegetable consumption: associated with reduced cancer and CV mortality Vegetables may have a stronger association with mortality than fruit Fresh vegetables were most protective, while frozen/canned fruit showed increased mortality Eating 7 or more portions of fruit and vegetables can reduce the risk of death by 42%
Bottom Line Eat more vegetables and fruit Eat less processed foods Eat whole grains Eat white meat over red meat, eat fish at leasttwice weekly Eat healthy oils and fat Increase intake of nuts, seeds, beans Dairy 1-2 servings a day Exercise more