fitness versus fatness - which is more important?

Doug Skrecky (oberon@vcn.bc.ca)
Thu, 8 Oct 1998 09:44:20 -0700 (PDT)

"US Weight Guidelines: Is it Also Important to Consider Cardiorespiratory Fitness"
International Journal of Obesity 22(Sup 2.): S2-S7 1998 Authors: CD Lee, AS Jackson and SN Blair

Abstract:

Background: The health consequences of weight ranges across low to moderate and high levels of cardiorespiratory fitness are known. Objective: To evaluate the validity of the 1995 US weight guidelines, while considering cardiorespiratory fitness.
Methods: We followed 21,856 men, aged 30-83 y, who had a complete preventive medical examination, including a maximal treadmill exercise test and body composition assessment. There were 427 deaths (144 cardiovascular disease (CVD); 143 cancer; 140 others) during an average of 8.1 y of follow-up. We used Cox proportional hazards regression to examine the relations among cardiorespiratory fitness, body mass index (BMI, kg/m2), and all-cause and CVD mortality.
Results: After adjustment for age, examination year, cigarette smoking and alcohol intake, we observed that men with a BMI of 19.0 to <25.0 and who were unfit had 2.3 times the risk of all-cause mortality (95% confidence interval (95% CI), 1.59-3.17, P<0.001) compared with fit men in this BMI group (reference category). Unfit men with a BMI of 25.0 to <27.8 also had a greater risk of all-cause mortality than unfit and normal weight men. Fit men of normal weight had substantially higher CVD mortality than fit men in each BMI group.
Conclusions: Unfit men had higher all-cause and CVD mortality than fit men. The health benefits of normal weights appear to be limited to men who have moderate or high levels of cardiorespiratory fitness. These data suggest that the 1995 US weight guidelines may be misleading unless cardiorespiratory fitness is taken into account.

Additional quote from text of the report:

"In this study, we do not intend to minimize the risk of overweight, but we do emphasize that increasing fitness may be more important than maintaining healthy weights. It is well documented that higher levels of physical fitness are associated with lower incidence of all-cause and CVD mortality. It is also established that an increase in fitness improves CVD risk factors and extends longevity. Thus we strongly recommend to public health policy makers the importance of maintaining acceptible levels of cardiorespiratory fitness.
Although our findings are limited to Caucasian men in middle and upper socioeconomic levels, this is the first study that presents data on longevity for the US weight guidelines categories, combined with cardiorespiratory fitness levels. Our data clearly show that greater longevity in men meeting the normal weight criterion of the 1995 US weight guidelines is limited to men who have moderate or high levels of cardiorespiratory fitness. These data suggest that cardiorespiratory fitness should be considered when defining body weight standards."

(from Table 2) Multivariate Relative Risk of Death

  BMI                  Fit        Unifit
19.0 - <25.0           1.0         2.25
25.0 - <27.8           0.96        1.68

>=27.8 (obese) 1.08 2.24

Additional comment from the poster:

Which is the more important factor affecting mortality rates: fitness or fatness? It looks like fitness is all important, and how fat you are is irrelevant. Data from other studies shows that dieters have an elevated mortality rate, while for those who exercise it is lower. The medical establishment's recommendations to lose weight in whose who are judged to be overweight is thus shown to be misguided. Sloth, not fatness kills. As far as diet goes, a number of factors are associated with decreased mortality rates. Increased fruit, vegetable, legume, grain fiber, fish, and nut intake appear to reduce mortality, while greater (non-fish) meat intake increases mortality. Research is ongoing to further clarify which fruits and vegetables are associated with reduced morality rates. Artichokes, garlic and tomatoes appear to be three stand-outs in this regard.