One of the oft repeated concerns about a carbohydrate restricted, high-fat diet is long-term effects. With globalization and a wide-variety of foods available in even remote locations today, it's increasingly difficult to find traditional populations whom may be ideally suited to assess the long-term effect of such a diet.
One such population does exist - the Masai of Africa - for whom meat, milk and blood are their daily dietary staples, a naturally low-carbohydrate diet that has been traditionally consumed for generations. They offer us a unique opportunity to assess how such a diet impacts the 'health risk markers' held dear in modern science and medicine.
Does their diet, high in fat, make them fat?
Does their diet, high in fat, make them hypertensive?
Does their diet, high in fat, lead to high cholesterol levels?
For decades many have assumed that a diet rich with dietary fat leads to obesity, high blood pressure and high cholesterol, which then is assumed to lead to heart disease and other chronic health problems.
In the June 3, 2008 issue of the British Journal of Sports Medicine a study investigating the Masai and their dietary habits and comparing them with rural and urban Bantu consuming different dietary practices is quite enlightening and tells us a story about how consuming dietary fat per se is not the underlying cause of obesity, high blood pressure or high cholesterol.
In the study published, Daily Energy Expenditure and Cardiovascular Risk in Masai, Rural and Urban Bantu Tanzanians, we learn that researchers investigated the dietary habits of three distinct populations within the same country - Tanzania - thus limiting confounding variables due to vastly different cultural conditions.
In total, the researchers investigated the health and health risk markers of 985 Tanzanian men and women - 130 Masai, 371 rural Bantu and 484 urban Bantu - with each group reporting very different dietary habits.
The Masai reported a high-fat, low-carbohydrate dietary pattern.
The rural Bantu reported a low-fat, high-carbohydrate dietary pattern.
The urban Bantu reported a high-fat, high-carbohydate dietary pattern, similar to a Western diet.
Which group to do think fared best?
Masai = 20.7
Rural Bantu = 23.2
Urban Bantu = 27.4 (as a whole, the group was, on average, overweight)
Incidence of Obesity (BMI at or higher than 30)
Masai = 3%
Rural Bantu = 12%
Urban Bantu = 34%
Waist-Hip Ratio (lower is better)
Masai = 0.87
Rural Bantu = 0.89
Urban Bantu = 0.93
Masai = 118/71
Rural Bantu = 134/80
Urban Bantu = 134/82
Prevalence of Hypertention
Masai = 4%
Rural Bantu = 16%
Urban Bantu = 21%
Masai = 3.89mmol/L (152mg/dl)
Rural Bantu = 3.60mmol/L (140mg/dl)
Urban Bantu = 4.50mmol/L (176mg/dl)
HDL (higher is better)
Masai = 1.08mmol/L (42mg/dl)
Rural Bantu = 0.91mmol/L (36mg/dl)
Urban Bantu = 1.08mmol/L (42mg/dl)
Masai = 2.09mmol/L (82mg/dl)
Rural Bantu = 2.13mmol/L (83mg/dl)
Urban Bantu = 2.69mmol/L (105mg/dl)
Masai = 1.36mmol/L (121mg/dl)
Rural Bantu = 1.45mmol/L (129mg/dl)
Urban Bantu = 1.61mmol/L (143mg/dl)
Total Cholesterol/HDL Ratio (less than 4 is 'ideal')
Masai = 3.72
Rural Bantu = 4.38
Urban Bantu = 4.53
LDL/HDL Ratio (the lower the better)
Masai = 2.21
Rural Bantu = 2.46
Urban Bantu = 2.69
ApoB/ApoA-1 Ratio (measure of LDL particle ratios, lower is better)
Masai = 0.74
Rural Bantu = 0.83
Urban Bantu = 0.81
So, there you have the major findings. What did the researchers conclude?
No! It couldn't possibly be their dietary habits, it must be that the "potentially atherogenic diet among the Masai was not reflected in serum lipids and was offset probably by very high energy expenditure levels and low body weight."
Now their level of physical activity certainly may be contributing to their overall health, but it's certainly not independent of their dietary habits. In fact, I would contend that while it's ideal to be active, that is not the driving force in 'health' or lack thereof - it's dietary habits that dominate our health outcomes, our level of activity may be important too, but activity in and of itself is no solution to a piss-poor diet.
We need, before activity, a proper diet to enable us to perform phyisical activity, not the other way around! So while the researchers here could not bring themselves to even consider that the habitual diet of the Masai - high-fat and low-carbohydrate - was the driving force in their good health and enabled high levels of activity, I'll say it!
Here we have evidence that a high-fat, low-carbohydrate diet, consumed habitually does not lead to obesity, high blood pressure and dyslipidemia, and it may, in fact, lead to beneficial long-term health and increased levels of activity in those habitually eating such a diet.