This presentation explains how the dangers to health which are linked to overweight and obesity have been grossly exaggerated. It goes to on show that in order to achieve optimum health and life expectancy the emphasis should be on physical fitness rather than weight loss. Verner Wheelock has been actively involved in research on Healthy Eating for the past 30 years. He has written and spoken widely on this subject. Currently he is Managing Director of Verner Wheelock Associates based at Broughton Hall in North Yorkshire. Prior to this he was Head of the Food Policy research unit at the University of Bradford. Verner has also been Special (Visiting) Professor in Food Science at the University of Nottingham.
This is a quote from an official public health strategy document for England. This clearly demonstrates that the incidence of overweight and obesity is expected to get worse in the future.
Here is another quote which concludes that obesity is bad for health and is extremely expensive.
The House of Commons Committee was obviously convinced that obesity is very bad news for public health in the UK.
Let us look at the actual data. There is no question that people have been getting heavier for the past 30 years or so. However the official statistics show that life expectancy has been increasing steadily over this period. Furthermore it is expected to continue increasing for the foreseeable future. There have clearly been very significant improvements in public health for life expectancy to be extended so much. How on earth can the House of Commons conclude that life expectancy will fall by 9 years ??
Despite the doom and gloom the number of deaths attributed to circulatory diseases (essentially heart disease and strokes) have fallen from over 600 per 100,000 to just over 200…….a phenomenal achievement! Deaths from cancer have remained reasonably stable over the period but recently appear to be declining. Deaths due to respiratory causes have fallen substantially while deaths due to infections are now negligible.
Despite the fact that there has been some increase in the number of people considered to be overweight and obese it is evident that public health has improved enormously as demonstrated by the improvements in life expectancy so there has got to be something wrong somewhere!
Body Mass Index is used to allocate people into different weight categories. This slide shows how to do the calculation.
This shows how the BMI is used to determine if a person is obese. According to the official public health policy anyone who is heavier than ‘’normal’’ is advised to lose weight. All the reports dealing with public health refer to those who are ‘’overweight and obese’’
This table gives some examples. A six-footer weighing 12 stones would be right in the middle of the ‘’normal’’ range. Another 2 stones would take that person into the ‘’overweight’’ category.
These official statistics show that there has been some increase in the average BMI starting in 1993. However during the last 4 years up to 2007 the values have remained virtually constant. Hence the dire predictions about how bad things will be in 2050 or whenever are not supported by the hard evidence!
Now let us consider the relationship between health and BMI. These results are derived from the National Health and Nutrition Examination Survey (NHANES) conducted in the USA. It was started in the 1970s and has continued until the present day. Large numbers of people have participated. They reported regularly to a centre where various measurements were taken by professional health workers which means that the quality of the data is absolutely first class. The normal BMI range has been taken as the benchmark and given a value of 1.00. The results show that the death rates in the overweight category are consistently lower than for those in the normal category. What is more the death rates in the obese I range are only marginally greater than 1.00. The study was conducted by Katherine Flegal and colleagues at the respected Center for Disease Control (CDC). The results were published in the authoritative Journal of the American Medical Association.
When the results for smokers are removed the picture is essentially the same.
These figures show the actual differences in total number of deaths again using the BMI normal range as the benchmark. The most recent results show that there were less deaths in the obese I range than there were in the normal range. The authors of the report attributed this to improvements in the quality of medical care.
Using the NHANES data the actual number of excess deaths has been calculated for various types of diseases in each BMI category. The normal range is used as the benchmark. This confirms what has been seen in the earlier slides with a smaller number of deaths in the overweight range. It is evident that there are more deaths due to diabetes in the overweight than in the normal range, which is the crucial argument used to support the traditional approach to weight loss/BMI. However when we look at the impact of other diseases/conditions the picture is totally different. It is quite obvious that there considerably fewer deaths due respiratory and infectious diseases, injury and other causes which include Alzheimer’s and osteoporosis. It is also noteworthy that this applies to those who are obese. Deaths linked to cardiovascular disease are lower in the overweight range which is in direct contrast to the conventional mantra. This information emphasises that it is essential to consider the whole picture. Furthermore official strategies must be supported by comprehensive data. Regrettably current policies appear to be based on anecdotal evidence which is restricted to a rather limited perspective.
As a consequence there had to be a major revision in the number of deaths linked to obesity in the USA. It is now less than 10% of what it had been previously. It comes as no surprise that these figures caused huge controversy when first published and were subjected to detailed scrutiny and criticism. However despite the best efforts of the critics no weaknesses were identified in the data or in the methodology used to compile the results.
This shows that similar results were obtained in a Canadian study. Confirmation has also been obtained from investigations in many other countries. The inevitable conclusion is that weight per se is not a critical factor in achieving good health except at the extremes. However we need to be just as concerned about those who are underweight as well as about those who are seriously obese. People who are as much as 4-5 stones above the normal BMI almost certainly will not improve their health. In fact there is no convincing evidence that losing weight is beneficial to health. Many slimmers who lose weight and finish up in the underweight category almost certainly are damaging their health.
So if weight is not critical what factors should be considered?? This slide shows how all-cause mortality for middle aged men women varies with the level of physical fitness. Low level would be a typical ’’couch potato’’ whereas a high level would be a person who does a brisk walk of 1.5/2 miles most days. It does not necessarily mean heavy sessions pumping iron. The results demonstrate the enormous benefits to health that can be achieved by taking a modest amount of exercise.
This investigation confirms the previous findings. In this study the fitness of men was assessed on 2 occasions separated by about 5 years. A comparison of those who were fit on both assessments with those who were unfit shows that for 60-year olds an unfit person is 4 times more likely to die than an unfit person. The middle column is highly significant because it demonstrates that it is never too late to start taking exercise which will improve life expectancy and. no doubt, general health.
In this slide once again those who are fit have a much lower mortality than those who are unfit. Furthermore there is little variation in death rates with BMI for those who are fit. However for those who are unfit the death rates are much higher with the highest rates for those in the normal and obese 2 ranges.
If the degree of fatness/obesity is assess by body fatness essentially the same result is obtained.
Here is a quote from a respected researcher.
Comment in a leading journal.
This just sums it up. Here in the UK we really ought to be asking why the results of the authoritative research quoted here has not been taken into consideration in the formulation of public health policy. Currently we are wasting huge sums of public money facilitating weight loss which may well be doing more harm than good not to mention what private individuals are doing in their attempts to lose weight.
The concern about being overweight and obese has been grossly exaggerated. Certainly those who are seriously obese have a higher than average death rate but there should be equal concern about those who are seriously underweight. However for the vast majority weight is not an issue with respect to health and there is no evidence to demonstrate that weight loss will be beneficial to health……in fact it may well do more harm than good! The results presented here provide convincing evidence that the greatest life expectancy is the in the BMI range ‘’overweight’’ which means that those in this category should not attempt to lose weight in order to get down to the normal range. For those who wish to remain healthy or even improve their health it is obvious from the facts presented here that the emphasis should be on exercise ….walking about 2 miles a day will produce enormous benefits. The basis for our current public health policies are fundamentally flawed and should be subject to an immediate thorough review conducted by people who are genuinely independent and objective. As things stand at present the public is being badly advised and money is being wasted.
Healthy Weight, Healthy Lives: <ul><li>A Cross-Government Strategy for England (March 08) </li></ul><ul><li>“ Britain is in the grip of an epidemic. Almost 2/3 of adults and 1/3 of children are either overweight or obese……These figures will rise to almost 9 in 10 adults and 2/3 of children by 2050.” </li></ul><ul><li>“ We are facing a public health problem that the experts have told us is comparable with climate change in both its scale and complexity” </li></ul>
House of Commons Health Committee Report <ul><li>May 2004 </li></ul><ul><li>“ On some predictions, today’s generation of children will be the first for over a century for whom life expectancy falls” </li></ul><ul><li>“ We estimate the economic costs of obesity at £3.3 – 3.7 billion per year and obesity plus overweight at £6.6 – 6.7 billion.” </li></ul>
House of Commons Committee of Public Accounts on Child Obesity <ul><li>December 2006 </li></ul><ul><li>“ Obesity is a causal factor in a number of chronic diseases….. </li></ul><ul><li> .….it reduces life expectancy by an average of 9 years” </li></ul>
FITNESS AND ALL-CAUSE MORTALITY <ul><li>13,344 men and women aged about 40 </li></ul><ul><li>283 deaths over 8 years </li></ul>FITNESS LEVEL Men Women All-cause mortality per 10,000 person years 1. (low) 64.0 39.5 2. 25.5 20.5 3. 27.1 12.2 4. 21.7 6.5 5.(high) 18.6 8.5
AGE, FITNESS AND ALL-CAUSE MORTALITY <ul><li>9777 men 223 deaths </li></ul><ul><li>4.9 years between fitness examinations </li></ul><ul><li>5.1 years follow-up </li></ul>Age Unfit/unfit Unfit/fit Fit/fit All-cause mortality per 10,000 man years 20-39 101.4 22.6 10.2 40-49 108.6 73.0 51.0 50-59 470.3 128.7 62.1 60+ 825.6 414.1 199.4
BMI, FITNESS AND ALL-CAUSE MORTALITY <ul><li>2603 adults in their 60s </li></ul>BMI Fit Unfit Mortality, relative rates Normal (18.5-24.9) 1.2 4.9 Overweight (25.0-29.9) 1.2 2.7 Obese 1 (30.0-34.9) 1.6 2.5 Obese 2 (>35.0) 1.2 4.8
BODY FAT AND ALL-CAUSE MORTALITY <ul><li>21.925 men aged 30-83 years </li></ul><ul><li>429 deaths </li></ul>BODY FAT Fit Unfit Mortality, relative rates LEAN <16.7% body fat 1.0 2.07 NORMAL 16.7-25.0% body fat 0.8 1.62 OBESE>25.0% body fat 0.92 1.90
Quotations on Obesity and Mortality <ul><li>"The idea has been greatly oversold that the risk of dying prematurely or of having a heart attack is directly related to relative body weight." — University of Minnesota Professor Emeritus Ancel Keys, W.O. Atwater Memorial Lecture, 1980 </li></ul>
Quotations on Obesity and Mortality <ul><li>"Neither coronary heart disease nor cancer, the two leading causes of death, was significantly associated with BMI." — Journal of Clinical Epidemiology, 1990 </li></ul>
Quotations on Obesity and Mortality <ul><li>"The establishment clings to the belief that weight causes disease and death just as people once insisted that the world was flat." </li></ul><ul><li>— Dr. Susan Wooley, Professor Emerita, University of Cincinnati, 1998 </li></ul>
Final Thoughts <ul><li>For most people weight is irrelevant to health </li></ul><ul><li>The key to good health is reasonable physical fitness </li></ul><ul><li>It is time for a complete re-think on public health policy </li></ul>30/07/10