Study suggests the burgeoning rates of obesity are due to people eating more, not exercising less

When an individual is aiming to lose weight, the popular wisdom dictates they need to eat less and/or exercise more. Of these two main options, my general belief is that dietary change gets generally more rapid and significant results than exercise in this respect. The evidence suggests that exercise (say walking, running or swimming) is not particularly effective for the purposes of weight loss, and this might have something to do with the fact that the number of calories burned during exercise are generally quite small. Plus, we have the fact that people who tend to exercise more tend to eat more too.

There are, I think, plenty of good reasons to take aerobic exercise, but weight loss does not seem to be one of them. If shedding pounds is the aim, then my advice is a more efficient strategy is to adjust the diet. Generally speaking, I advise here a diet generally low in carbohydrate. Carbohydrate (particularly sugary and starchy ones) tend to cause insulin secretion, which has a key role to play in fat accumulation in the body as explored recently here. Plus, a lower carb diet, particularly if it is rich in protein, tends to satisfy more than a higher carb one, which very often causes individuals to eat less without consciously restricted the amount of food they eat. In other words, this sort of diet can very often lead individuals to lose weight without hunger.

The potential for diet and exercise to promote weight loss popped into my mind when reading about a study which attempted to explore which, if any, of these lifestyle factors is the cause of the rising rates of overweight and obesity in the USA. The study was presented last week at the European Congress on Obesity in Amsterdam, the Netherlands. You can read a report on the study here.

Scientists assessed the metabolic rates of about 1400 adults and about 950 children to calculate the number or calories required each day for stable weight in the adults and normal growth in the children.
They also calculated the likely calorie intake from the 1970s to early 2000s that would account for the rise in overweight and obesity seen over this time. They also estimated the actual calories intakes from data relating to food production and wastage.

Now, with all of this information, the scientists were in a position to ascertain what proportion of the additional calories responsible for increasing weight in Americans appears to have come from increases in food intake. It turns out that in children, the weight changes seen over the 30-year period assessed in the study could be entirely explained by apparent increases in food consumption. In adults, the vast majority of weight increase could be explained in the same way.

Now, this study is quite theoretical and we’re going on reports of the study rather than the study itself. However, if the data stacks up, then this study appears to show that in the USA at least, burgeoning rates of overweight and obesity appear to be the essentially the result of eating more, not exercising less. And this would mean, I think, that in terms of reversing the trend, the emphasis should really be on diet, not exercise.

6 Responses to Study suggests the burgeoning rates of obesity are due to people eating more, not exercising less

  1. Trinkwasser 13 May 2009 at 5:27 am #

    Something on the subject from the ever reliable Michael Eades

    anecdotally the Healthy High Carb Low Fat diet left me totally knackered, which I now realise was down to rapidly swinging glucose and insulin levels and humungous insulin resistance. I would do ten minutes gardening then have to sit down and recover for an hour. Changing the diet radically improved my energy levels which permit me to exercise more, which feeds back into further improved IR

  2. Chris 14 May 2009 at 1:15 pm #

    Trinkwasser, thanks!
    Mr Eades take on things is not far removed from my own. Especially, his views upon the endemic nature of the culture which permits the continuance of this sad state of affairs. Of course, Mr Eades is describing the state of affairs in the USA and not the UK, but I think that most of the propositions would be applicable.
    Criticism of the regulator(s) translates well. Our own Food Standards Agency has to work within some constraints and it asking a lot to expect them to show a lead where the sort of attitudes Eades alludes to is endemic elsewhere. Our FSA has a large remit and does considerable good work, but it is struggling to get correct and effective messages to those who need it most.

    Once dietary cholesterol (limit eggs to 3pw) was the cause celebre. Now eggs are OK. Coincident (remarkably so) with the dropping of the ‘limit eggs message’ was the launch of the ‘mutton fat down the sink blocks drains’ anti-saturated fat campaign by the FSA. So fat replaces eggs and cholesterol as the cause celebre, the FSA can save the nation significant sums by addressing the cause of CVD/CHD they say, but then only weeks into the campaign comes the Mente review which casts great doubt upon the Sat-Fat hypothesis. I am far from pro fat, for sure we all need some in our diet, but I have huge reservations about possible unintended consequences of the campaign.
    At best the consumer advice side of the FSAs work has marginal positive effect, possibly contributes to the problem unwittingly, and arguably makes matters more confusing for the wider public – all IMHO. Worse still, it looks too easily influenced by ‘partners in industry’. Again IMHO.

  3. MAC 16 May 2009 at 3:57 pm #

    While I also do not believe that a calorie is not a calorie, someone on a low carb forum made an interesting comment about this study. Giving up smoking usually leads to weight gain and this study period is when there has been a reduction in smoking in the US. I wonder if they accounted for this variable in this study.

  4. Trinkwasser 16 May 2009 at 5:18 pm #

    Personally I’m quite in favour of saturated fat: it gives me prolonged energy without the BG and insulin spikes and keeps my HDL up and LDL down AS LONG AS I eat anatomically correct quantities of carbs, in my case around 60 – 100g/day is my sweet spot.

    The problem with the FDA and other such “authorities” is that they are looking for a simplistic one size fits all recommendation. It’s plausible that a high carb low fat diet works for 2/3 of the population but certainly not for the 1/3 that I am in. So in trying to make things better for the majority they are killing the minority.

    That may not be a bad thing from the point of view of their sponsors, mostly carbohydrate manufacturers and drug pushers (the drugs overcome the bad effects of the carbs) and in the FDA’s case their connections to Unilever, remove the noncompliant from the gene pool and increase market share.

    (I also suspect my numbers may be optimistic)

  5. Chris 4 June 2009 at 3:48 pm #

    I take your point, we are all individuals for whom a ‘one size fits all’ approach may be inadequate.
    You and I have a number of things in common and not least that our particular interest in these matters is driven by the concern for our own health and the need or desire to manage our conditions. I openly declare that I am aged around 50, overweight and T2 diabetic. I don’t think I suffer from depression or SAD, but if I don’t manage my diet properly and suffer protracted raised BG then my diabetes can really mess with my head. Successive experience like that is what convinces me of a very powerful link between food, mood, and health.

    We are not alone to experience some kind of lifestyle or health epiphany. Dr Briffa himself describes one as being pivotal in his choice of career direction; many suffer the stress and drudgery of the 0745 commuter belt living for decades and then elect to make drastic lifestyle changes. We both know the anxieties of dragging 38 tonnes around the nation.

    Our insight is invaluable, because while people are blessed with good health they give very little thought to it. We wonder with hindsight, had we been better informed, could we have lived our lives differently and avoided the pits into which we have fallen. Undoubtedly yes! So we are a bit like missionaries trying to spread the good word; but the healthy folks have enough going on their lives catching the 0745, or whatever, without having to listen to us. Simply, they do not yet see the point.

    We have to be exceedingly grateful to Dr Briffa for running this site. He brings to us pertinent information and does so in a way which appears balanced. He permits us our comments and opinions in a way which appears highly democratic. The site is a great place for the exchange of views and is the antidote to the aspects of society that skew the pursuit and presentation of knowledge.

    In a sweeping statement of reductionism, for which I am strikingly unqualified to make, I would say that obesity, insulin resistance, and T2 diabetes represents progression down a progressive pathway of metabolic dysfunction. That said, the questions are how do folks avoid be driven down that pathway, and if they recognise themselves as being on it, what should they do about it?
    I guess a persons prospects of getting of it depend upon how far they have gone down it. For sure, the further one goes, the harder it is to come back. In short the strategies that those on the path must employ to manage their condition must be tailored to the extent of their condition. However, the strategies that may prevent healthy people from being driven down the path in the first instance, may be relatively consistent. Our opinions are invaluable, and better for being set in context.

    It is all very complicated and in the broadest sense our health service does not support our aspirations; no wonder so many elect for the alternative route of metformin.

    High fives, Trinkwasser! – you have introduced some good links! It is a pity we cannot converse at greater length and more privately.

  6. Bridgette 13 January 2010 at 3:20 am #

    Obesity and diabetes is a growing problems nowadays. It is caused by todays lifestyle which does not involve lots amount of exercise. Most people are just happy sitting in their office chair and they do not even want to sweat.

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