Thursday, July 14, 2011

The Great Monetary Effect of Calorie Reductions

I recently reviewed this research article and as it supports the things that I believe to be true - I like it!

The reference is:

Dall, T. M., Fulgoni, V. L., Zhang, Y., Reimers, K. J., Packard, P. T., & Astwood, J. D. (2009). Potential Health Benefits and Medical Cost Savings From Calorie, Sodium, and Saturated Fat Reductions in the American Diet. American Journal of Health Promotion, 23(6), 412-422

In this study, the scientists used modeling or simulation to estimate the impact of certain dietary changes on health and how those changes would impact spending on treatment for specific conditions.  The data on the population was gathered through existing sources, such as national survey and examination databases that track our behavior and health over decades (which is why we know things like how much more we weigh, how much less we do, how rates of hypertension and diabetes have risen, etc etc).

As I continue to read articles that refer to TEI and TEE (total energy intake and expenditure) the formulas  become more familiar to me.  Many of the researchers refer to "the" doubly labeled water technique.  This appears to be gold standard research which captures the absolute total energy burned and consumed by persons under laboratory controlled conditions.  The results only involve small groups of people, because the technique is costly and intricate but are the basis for most equations. The formulas begin with some baseline numbers that are tweaked with factors (mathematical) related to age, gender and activity level.  

This study included a formula for estimated energy requirement or EER.  I like this one.  It was used to compute one of the findings that I embrace.  I will now share both with you. 

With their formulas and modeling the researchers looked at the impact of reducing sodium intake in persons with uncontrolled hypertension (high blood pressure), lowering saturated fat intake for those with high LDL (bad cholesterol) and lowering caloric intake to address overweight and obesity.  These three things did save billions of dollar each year over a simulated four year period, HOWEVER, the strategy that saved the most money - 58 billion dollars a YEAR, was reducing calories just by 100 - per person.  The researchers isolated this to model a population at a certain physical activity level at 100 cals a day less than usual without changing anything else.  So, many people eat 2000 cals a day (or much more) and instead they were projected to eat 1900 - every day.  This strategy reduced the number of overweight and obese Americans by 71million (58 billion dollars saved).  The sodium and fat calculations only reduced medical expenditures by  2.3 and 2 billion dollars, respectively (per year).  Thus it was concluded that the focus should be on getting people to eat less calories.   When the research model calculated a 500 calorie decrease, perhaps 1500 calories a day - the model predicted that nearly all of US adults would be in the normal weight category in four years!  
That brings us back to Swinburn's article which suggested that Americans are consuming and extra 500 calories since the 1980s and that the extra is equal to a fast food burger (intake) or two hours of extra walking (expenditure)!   

Now here is the formula for estimated energy requirement - male and female - though you have to plug in some of your own values and you MUST do the math according to the rules of operations or whatever it is called when you have to do it in a very specific order to get the right answer (Melanie - you can ALWAYS comment on these posts on the website :)) 

EER=
[662-(9.53 x age)] + [PAL x (15.91 X weightkg)] + (539.6 x heightm )  
for males 


[354-(6.91 x age)] +[PAL x (9.36 X weightkg)]+ (726 x heightm ) for females


choose a PAL here

sedentary 1- 1.4
low active 1.4-1.6
active 1.6-1.9
very active 1.9 - 2.5
or
low 1.4 - 1.69
moderate 1.7-1.99
high 2-2.4

You can use this link to convert your weight and height to kg and meters. 

When I did it for myself it came to just over 1800 calories - I usually eat 1600-1800 depending on my activity levels - so I think it was pretty accurate. 

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