The IEA has just published a report which concludes that:
“The rise in obesity has been primarily caused by a decline in physical activity at home and in the workplace, not an increase in sugar, fat or calorie consumption” (1).
The report relies mainly on official statistics but is also heavily dependent on the conventional view that obesity is the result of consuming more calories than are expended. Despite the fact that this concept is the basis of official policies in the UK and in many other countries and organisations there are compelling reasons why it is fundamentally flawed. In this blog I will explain why it is not calories per se but sugar/refined carbohydrates, which is the fundamental cause of obesity. In addition I will assess the quality of the information presented on how the consumption of sugar has changed over the past 30-40 years.
The author Christopher Snowdon concludes that the evidence shows that in Britain the per capita consumption of sugar, salt, fat and calories has been falling for decades. In particular, sugar consumption has fallen by 16 per cent since 1992 while calorie consumption has fallen by 21 per cent since 1974.
QUALITY OF THE DATA
The main sources of information are the National Food Survey (NFS) up to 2000, when it was replaced by the Family Food survey. Because these 2 surveys each have different basis, it is not possible to obtain a continuous tracking of the changes. It was not until 1993 that obesity statistics were commenced. Although there has been a steady increase in the incidence of obesity in adults since then the pattern in children is rather different. The information was first collected in 1995 and then there was a peak about 2004 and the decline in recent years has reduced the incidence in 2012 to almost the same level as in 1993.
Although the NFS has limitations it is probably fair to conclude that it does provide a reasonably reliable indicator of trends. This certainly applies to total calories which declined from 2210 in 1980 to 1750 in 2000. The NFS also showed declines in total fat from 106g in1980 to74 in 2000. The corresponding values for total carbohydrate, which of course includes sugar were 264 and 218. The author of the IEA report presents a graph which shows that “sugar” has declined between 1992 and 2012. Presumably the data for the period up to 2000 is from the NFS. I have gone back to the original, which makes it clear that the calculations for the intake of nutrients does not include information on soft drinks and alcoholic drinks and confectionery. All of these contain sugar and if an accurate assessment of the trend is to be determined it is essential that allowance is made for the contribution from these sources. I have also been in touch with the team which is responsible for the food statistics, which has confirmed that there is no reliable information available on the intake of sugars prior to 2000
The difficulties of estimating the intake of sugar are exacerbated by the fact that it is present as an ingredient of many different processed foods, because it is inexpensive and makes foods attractive to the palate. Many of the “low fat” variations of foods are actually formulated by removing the fat and replacing it with sugar. Yoghurts are a typical example. In order to calculate the total intake for the population it is necessary to know the volume of sales and the exact nutrient composition of each particular food. It is a huge and difficult task to do this properly. In Australia the bureau of Statistics simply decided to abandon attempts to produce a reliable value because it was too difficult (and expensive!). Although the UK attempts to deal with this problem, the complexity of the food market and the rapid rate of change mean that it is virtually impossible to obtain reliable information
To sum up, in all probability there has been a substantial drop in the consumption of calories and possibly also in fat. However when it comes to sugar, reliable information is hard to obtain but we can be confident that there is absolutely no credible evidence that there has been a decline in the consumption of sugar. In the light of the substantial increase in the amounts of soft drinks sold, coupled with the growth of sugar-containing processed foods, there are strong indications that total sugar consumption has increased steadily in the period up to 2000.
In recent years, some people are actively cutting down on their sugar consumption, which could mean that for a sector of the population sugar consumption could continue to increase even though the amount for the population as a whole remained constant.
Finally we have to place this in the context of what we know about nutrition. Although many still hold to the view that obesity is caused by consuming more calories than are expended, this has been subject to severe criticism. An excellent example is the work of Zoe Harcombe in her book “The Obesity Epidemic”(2). For example it has been shown that weight loss by calorie reduction simply does not work (3).Invariably this involves a reduction in fat, which can actually result in an increase in the amount of carbohydrates consumed. Furthermore there is convincing evidence that it is sugar and the refined carbohydrates which are the fundamental cause of obesity (4).In particular, there are compelling studies showing that it is the composition of the diet, which is crucial for obesity to occur. Specifically diets which are high in sugar/refined carbohydrates predispose not only to obesity but also to diabetes, heart disease, various cancers and Alzheimer’s Disease. Conversely, there is now a body of knowledge which demonstrates that diets which are low in carbohydrates and high in fat (LCHF) can be beneficial with respect to a range of diseases/conditions(5). These include heart disease, blood pressure, cancers, body weight and overcoming Type 2 Diabetes.
It follows from this that the crucial issue is the intake of sugar and refined carbohydrates. As I have explained above the Information on sugar is not reliable. The case presented by Christopher Snowdon does not stand up to scrutiny. There is no “English Paradox”. In any event, it is not obesity per se that should be a matter of concern with respect to public health. Much more critical is the growing incidence of diabetes, which has doubled in the past 15 years or so (4). There is absolutely no doubt that this is caused by excessive consumption of sugar and refined carbohydrates.
This report has rather uncanny parallels with what has been happening in Australia, where 2 academics from the University of Sydney have claimed that there is an “Australian Paradox “(6). This was based on a conclusion that the consumption of sugar had declined over the same period that obesity had been increasing. This was disputed by an economist Rory Robertson, who showed convincingly that there was no credible data to demonstrate how the consumption of sugar had changed over the relevant period. He concluded that:
“All in all, we are left with a clear sense that there is no “Australian Paradox”, just an idiosyncratic and unreasonable assessment – and avoidance – of the available sugar data by those who coined the phrase” (7).
Because of this he forced the university to set up an inquiry into the activities of the academics with respect to manipulation of the data. The results of the inquiry have recently been announced. Although Christopher Snowdon has claimed that the academics were exonerated, the reality is that the findings were somewhat unequivocal.
Although the adjudicator dismissed the allegations about “research misconduct” it was clear that he was not impressed by the quality of the original “Australian Paradox” paper. He concluded that the paper was not tightly written and contained a number of arithmetic errors. He expressed the view that important new findings would usually be published in a high-impact, rigorously peer-reviewed journal. Subsequently the results would be considered in special edition publications of conference journal format. Clearly this had not been done as the original was published in what was regarded as a ‘soft’ journal, where the quality controls are less stringent. As a consequence it was recommended that a new one be prepared which specifically addresses the key factual issues raised in the inquiry. Furthermore this paper should be written in a constructive manner which respects the issues relating to the quality and reliability of data, raised by Rory Robertson (8).
However, from a close reading of the report it is obvious that there really has been no attempt to deal with many of the serious allegations made by Rory and that effectively it is a rather poor attempt at a “whitewash” (9). A further detailed submission has been prepared by Rory and it is to be hoped that ultimately the issue will be addressed properly (10).
So it is evident that this report by IEA does not make any useful contribution to our understanding of the causes of obesity and should be ignored. The fact remains that sugar and refined carbohydrates lie at the root of many of the public health problems not only in the UK but right across the globe.
- Zoe Harcombe (2010) “The Obesity Epidemic” Columbus