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The Obesity Paradox What happened when the diet experts put their healthy eating programs and advice to the test? Not fad diets written by crackpots, celebrities, or self-styled wellness gurus, but the lifestyle diets recommended by major medical institutions and embodied in government guidelines on healthy eating. Not on rats or mice in labs, but on real people in the real world eating real food. Women's Health Initiative (WHI) Dietary Modification Trial 48,835 postmenopausal women were randomly assigned to either their regular unrestricted diet or to a healthy low-fat, high fiber diet. By the end of the study, the dieters were eating 29% fat, compared to 37% in the control group, and ate about 25% more fruits and vegetables, grains and fiber than the group on your typical American diet. |
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After eight years they discovered there was no difference in the incidence of breast cancer, colon cancer, heart attacks or strokes among those who ate "healthy" and those who ate whatever they pleased. The researchers concluded: "A dietary intervention that reduced total fat intake and increased intakes of vegetables, fruits, and grains did not significantly reduce the risk of CHD (coronary heart disease), stroke, or CVD (cardio-vascular disease) in postmenopausal women." Not only that, but among the women who had heart disease symptoms at the beginning of the study, the low-fat diet slightly increased their risks for heart disease. |
"A dietary intervention that reduced total fat intake and increased intakes of vegetables, fruits, and grains did not significantly reduce the risk of CHD, stroke, or CVD in postmenopausal women." |
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They added: "We found no evidence that lower intake of total fat or specific major types of fat was associated with a decreased risk of breast cancer." Also, the women who'd been on low-fat diets before the study began had slightly higher risks for breast cancer than women who'd been eating the most fat. At the same time women who had managed the most reduced fat diets had the highest risk for breast cancer. Lastly they wrote: "A low-fat eating pattern does not result in weight gain in postmenopausal women." Note, they didn't claim the low-fat diet made you thinner, rather it didn't make you fatter. Subjects lost some weight at the start, but regained it before the end of the trial, despite eating 361 fewer calories a day than at the start of the study. At the end, the researchers found weight change differences between the two groups of less than two pounds. Multiple Risk Factor Intervention Trial (MR. FIT) |
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This was one of the largest medical studies ever performed on humans involveing 28 medical centers and 250 researchers costing $115,000,000. The researchers selected 361,662 men who were at very high risk to hopefully ensure a statistically significant result. They cut cholesterol consumption by 42%, saturated fat consumption by 28% and total calories by 21%. Yet even then they didn't succeed. Blood cholesterol levels fell only a modest amount and, more importantly, coronary heart disease was unaffected. Its originators called the results "disappointing" and state in their conclusions: "The overall results do not show a beneficial effect on Coronary Heart Disease or total mortality from this multifactor intervention." |
"The overall results do not show a beneficial effect on Coronary Heart Disease or total mortality from this multifactor intervention." |
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UCLA research Researchers analyzed the Acute Decompensated Heart Failure National Registry and the more than 108,000 cases of acute heart failure in hospitals nationwide from October 2001 through December 2004. Adjusting for every contributing factor, they found for every 5 unit increase in BMI the risk of dying dropped by 10 percent. Among men with symptoms of heart disease, the overweight tend to live longer than their normal-weight counterparts. Researchers found that among nearly 6,900 male veterans assessed for symptoms of heart disease, those who were overweight were less likely to die over the next 7.5 years compared with normal-weight men. INVEST trial A prospective, randomized international study of some 22,000 patients with hypertension and coronary artery disease age 50 and up. The patients got cardiovascular workups including BMI (body mass index) calculations, and were followed for an average of 2.7 years. |
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The INVEST findings: Compared to normal weight patients, thin patients had 74% higher risk of both death and having a heart attack or stroke, and overweight patients had 29% lower risk. But the obese had the lowest risks of all, nearly half that of normal weight patients. Adjusted for diseases, such as kidney disease and congestive heart failure, and health risk factors the researchers found being overweight and obese was associated with lower risks, 1/3 to 1/4 that of patients of normal weight. Interestingly, being thin had a 52% higher risk; advancing age a 63% higher risk; smoking rendered a 40% higher risk. They concluded: "Our study is in agreement with previous studies that observed an obesity paradox in patients with previous cardiovascular disease... Our results suggest a protective effect of obesity in [these] patients." |
"Our study is in agreement with previous studies that observed an obesity paradox... Our results suggest a protective effect of obesity in [these] patients." |
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Growing Up Today Study (GUTS) A study led by Allison Field at Brigham and Women's Hospital and Harvard Medical School examining the health and lifestyles of more than 16,000 children, ages 9 to 14. The study found, regardless of overweight status, dieting children gained more weight compared to children who didn't. This confirms another study by these same researchers finding girls who were frequent dieters were nearly 4 BMI (body mass index) points higher versus never or rarely dieting kids. This after accounting for other factors, including physical activity, television watching, etc. Neither could the researchers find a connection between soda or snack (so-called junk food) consumption and weight among these kids after 3 years. The bottom line, fat kids didn't eat more sweets than the thin ones. Two More The National Institutes of Health conducted an expert review showing weight gain with age for both men and women reduces death rates; while dieting, weight loss or fluctuating weights (yo-yoing), increases the risk of actual death, cardiovascular diseases, type 2 diabetes and cancers. |
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David Garner, Ph.D. and Susan Wooley, Ph.D., reviewed 500 studies on weight in Clinical Psychology Review and concluded: "Multiple researchers, using a variety of methodologies, have failed to find any meaningful or replicable differences in the caloric intake or eating patterns of the obese compared to the non-obese to explain obesity." All this evidence contrary to the popular wisdom is often called the "obesity paradox." Study after study showing fat people living longer and no connection between fat laden diets and poor health nor between so-called "healthy diets" and better health. The facts are as obesity rates increase in the U.S., heart disease death rates have been dropping for more than five decades -- 22% between 1993 and 2003 alone. |
"Multiple researchers, using a variety of methodologies, have failed to find any meaningful or replicable differences in the caloric intake or eating patterns of the obese compared to the non-obese to explain obesity." |
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This is only a paradox if being thin really should be healthier than being fat, especially as we age. This is only a paradox if a low-fat, low-salt, low-sugar or whatever the experts regard as a healthy diet really should be healthier. But what if those beliefs are overstated or, as the evidence suggests, wrong? Framingham Heart Study This study was set up by Harvard University Medical School in Framingham, Massachusetts in 1948, and is still going on today. This was this study that gave rise to the dietary 'risk factors' with which we all are so familiar today. |
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First, the researchers measured cholesterol intake and compared it with blood cholesterol. Even though subjects consumed cholesterol over a wide range, there was little or no difference in the levels of cholesterol in their blood. (It is interesting that women with the highest blood cholesterol levels also had eaten the least cholesterol.) Next, they studied intakes of saturated fats, but again they could find no relation. There was again no relation when they studied intake of total calories. They even considered the possibility that something was masking the dietary effects, but no other factor made any difference. After twenty-two years of research, the researchers concluded: "There is, in short, no suggestion of any relation between diet and the subsequent development of CHD in the study group." |
"There is, in short, no suggestion of any relation between diet and the subsequent development of CHD in the study group." |
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After a further twenty-seven years, the Journal of the American Medical Association (JAMA) carried a follow-up report that showed dietary saturated fat reduced occurences of strokes. As these tend to affect older men, they wondered if a fatty diet was causing those in the trial to die of CHD before they had a stroke. But the researchers discount this, saying: "This hypothesis, however, depends on the presence of a strong direct association of fat intake with coronary heart disease. Since we found no such association, competing mortality from coronary heart disease is very unlikely to explain our results." The Paradox After almost 50 years of research on tens of thousands of people, the researchers are saying they still can find no relation between a fatty diet and heart disease. These are not results from fringe groups or small, short-term studies. These are not slight statistical anomalies culled from meta-studies. These are mainstream, controlled cohort studies done to prove the case for the very dietary interventions that did not work. You have to wonder why are we constantly told to loose weight to some prescribed "good" body mass index when the overweight outlive those at the supposed ideal. Or why they tell us a low-fat, low calorie, high-fiber diet with more fruits and vegetables will help us live longer, but when they've actually tried these diets they didn't work. Most importantly, why is it when their recommendations don't work as they expect they don't question the original hypothesis, but try to explain how the evidence they just produced is wrong. Could be the paradox is not in the unexpected results, but in the continuing expectations despite the evidence of the results. |
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How We've Come to Believe That Overeating Causes Obesity Diet and Fat: A Severe Case of Mistaken Consensus Inquiring Minds Want to Know: When are Food and Health Claims Real? Our Healthiest Weight is Not What we Think |
Could be the obesity paradox is not in the unexpected results, but in the expectations despite the results. |