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DavidGillespie BigFatLies BigF@tLies
David Gillespie and 'Big Fat Lies' on Exercise
Chapter 3 of �Big Fat Lies� by David Gillespie is called �Exercise Won�t Help You Lose Weight, Either� and despite the fact that Pubmed returns 4949 articles for either �exercise� or �physical activity� in the title or abstract as well as �weight loss� ([Title%2FAbstract%29%20OR%20physical%20activity[Title%2FAbstract]%29%20AND%20weight%20loss[Title%2FAbstract Pubmed Research Articles on Exercise/Physical Activity and Weight Loss]), this chapter has a measly seven references and only three are reported to directly support his claims! Hardly a thorough review of the literature, especially considering that none of them are summary papers or meta-analysis!
1. The first paper is Fatness leads to inactivity, but inactivity does not lead to fatness: a longitudinal study in children A very interesting study that ultimately states that �Although there may be many benefits to PA, the findings of this study, coupled with the limited success of PA interventions aimed at improving BMI, imply that public health strategies may need to target energy intake to curb the year-on-year rise in childhood obesity.� It concludes that childhood obesity is most likely not caused by a decrease in physical activity, that more focus on energy intake is likely to be more successful in addressing weight gain but DOESN�T say that exercise won�t help you lose weight (but overweight children are less likely to participate).
2. The next paper is the American Heart Association and American College of Sports Nutrition Review, (Physical Activity and Public Health : Updated Recommendation for Adults From the American College of Sports Medicine and the American Heart Association Circulation. 2007;116:1081-1093; 2007. From this paper David Gillespie claims that �After reviewing all of the available evidence, they recommend 30 minutes of moderate-intensity physical activity five days a week to �promote and maintain health. Noticeably absent from the guidelines is any suggestion that exercise would definitely lead to weight reduction.�
For starters, promoting and maintaining health is quiet separate from weight loss! The final point in those key points listed in the paper�s recommendations also state that �Because of the dose-response relation between physical activity and health, persons who wish to further improve their personal fitness, reduce their risk for chronic diseases and disabilities or prevent unhealthy weight gain may benefit by exceeding the minimum recommended amounts of physical activity.� While preventing unhealthy weight gain isn�t the same as weight loss, it does clearly identify the difference between health and directly affecting body weight, as does the following quote on p 1084 �To help prevent unhealthy weight gain, some adults will need to exceed minimum recommended amounts of physical activity to a point that is individually effective in achieving energy balance, while considering their food intake and other factors that affect body weight.�
Back to �Big Fat Lies� and David Gillespie continues directly after the aforementioned quote with; �The best they could come up with was: �It is reasonable to assume that persons with relatively high daily energy expenditures would be less likely to gain weight over time, compared with those who have low energy expenditures. So far data to support this hypothesis are not particularly compelling.��
This quote from the paper is from the section entitled �Obesity, Gaining, and Losing Weight.� from page 1087. In the sentence immediately prior to David�s quote it says �While more information is gathered on the varied causes of obesity, it seems vitally important for public health efforts to address both energy expenditure and energy intake.�
In the paragraph following the quote, the paper states �Still, despite the intuitive appeal of the idea that physical activity helps in losing weight, it appears to produce only modest increments of weight loss beyond those achieved by dietary measures and its effects no doubt vary among people (64). A review of studies where exercise or physical activity was the sole intervention or was added to caloric restriction found only modest weight loss resulting from exercise (57). However, these studies were relatively short term and the effect of physical activity on weight loss over the long term remains unclear.�
Modest is very different from �Noticeably absent from the guidelines is any suggestion that exercise would definitely lead to weight reduction� and that is beyond that using dietary measures! At best long term remains unclear is also a far cry from it being a waste of time!
Further on in the same section, appears the following sentence �For most adults in the US today, consumption of calories is unimpeded while expenditure of calories via physical activity is difficult; thus it is unlikely that without some self restriction of calorie intake or expanded opportunities and greater encouragement for physical activity many people will become or continue to be overweight or obese.�
The final few sentences of that section clearly state the intention of the advice �In the mean time, because of the documented obesity-independent benefits of regular physical activity (25,37,40), adults regardless of body size or shape should be encouraged to meet the moderate intensity, minimum of 30 min/d on 5 d/wk guideline.
For individuals who achieve this level of activity, but remain overweight, an increase in their physical activity is a reasonable component of any strategy to lose weight� (emphasis added by myself).
It would be safe to suggest that this paper clearly DOES support physical activity for weight loss, with a lot more than a suggestion and that the quotes from the paper and conclusions drawn aren�t accurate representations of the paper�s contents or recommendations!
3. The Effect of Physical Activity on 18-month Weight Change in Overweight Adults from the Journal Obesity 2011 Jan;19(1):100-9 From this paper David states that �The study ran for 18 months, an unusually long time for this kind of study. After all that time and effort, however, the results were disappointing to say the least. The first group (the folks with the booklet and an encouraging wave) did pretty well. They averaged about 15 minutes of exercise per day. The folks in the moderate group only managed to exercise 14 minutes a day, despite all of the help � which suggests that their meetings with the trainer were a waste of time and money. The hard-core group did quite a bit better, managing to average 31 minutes of exercise a day, but that was still half of what they were supposed to be doing.
On the diet front, everyone in the study took the researchers advice and didn�t worry about it. There were no differences between the groups in terms of their average calorie intake. The percentage of bodyfat (about 30 per cent) for all three groups were pretty much the same at the end as it was at the start. The first group lost an average of 0.5 kilograms, the moderate group knocked off 0.7kilograms and the heavy hitters in the hard-core group managed a great big 0.8 kilograms�. None of the groups managed to lose one whole kilogram in a year and a half of exercising.�
Here is a number of quotes from the paper, again demonstrating that there is research showing a benefit to weight loss (probably mixed in with those 4940 odd papers that didn�t make the cut!)
p.100 �Physical activity (PA) when coupled with a reduction in energy intake enhances initial and long-term weight loss (3)��US Dietary Guidelines for Americans (4) recommends 60 min of moderate-intensity PA for the prevention of weight gain. More recent literature reviews conclude that PA ranging from ~150�250 min/week results in weight loss of <3 percent of initial body weight (3,5).�
p.106 The first sentence of the discussion section says �Two recent comprehensive reviews of the literature have reported that PA interventions result in a modest decrease in body weight.�
�The literature review conducted for the Physical Activity Guidelines for Americans (5,20) concluded that weight loss is typically 1�3% of initial body weight in response to =180 min/week of PA, with PA <150 min/week resulting in no reduction in body weight. The American College of Sports Medicine concluded that 150�250 min/week of PA results in a similar magnitude of weight loss (3).�
From the study we know that both groups received considerably counselling with a goal of getting the MOD group to 150mins/week and the HIGH group to 300 mins/week. The study states that �At 18 months, the PA was 66 min/week and 155 min/week above baseline levels in MOD-PA and HIGH-PA�. Thus the intervention didn�t reach the target activity levels and are consistent with the aforementioned guidelines; these levels of activity didn�t result in significant weight loss (although their was a trend in those who lost weight to reduce energy intake � which would also be a part of any sensible weight loss plan!).
Furthermore the study listed a number of other papers and reviews where weight loss was noted, so to ignore them and just quote this study in supported of the exercise and weight loss hypothesis is far from full disclosure!
Despite the fact that these studies don�t really support David Gillespie�s contention that exercise won�t help you lose weight, other studies do! Cherry picking studies does nothing to enhance knowledge on a topic and is usually used to support a pre-determined idea or outcome, which is the opposite to the way that science works (where you review the literature and THEN draw conclusions!).
As we have shown in this post Science DOES Support Using Exercise For Weight Loss, a full review of the literature leads on to very different conclusions with regards to how effective exercise is in helping with weight loss (as well as whether or not the science is �settled� in either direction). Almost everyone needs to exercise more, regardless of their motivation for getting involved, it will benefit you in so many ways, it should become a lifelong habit!
For more information on the reality of the literature regarding Big Fat Lies by David Gillespie and Sweet Poison by David Gillespie please click on the links for the specific topics such as Facts on Fructose that David Gillespie gets wrong! Exercise Evidence that shows that Big Fat lies misrepresents the research. Lipid Legitimacy questions David Gillespie's association between vegetable oils and modern diseases.
David Driscoll
