The relationship between overweight and cardiovascular disease

From the European Heart Journal.

Separate and combined associations of obesity and metabolic health with coronary heart disease: a pan-European case-cohort analysis

Very interesting study, given the size of the cohort (520,000). Most interesting finding is that overweight and obese people with normal metabolic indicators (eg, BP), likely as a result of good diet and/or regular exercise, have better outcomes than a person with normal body weight and poor metabolic indicators, likely a sign of poor diet and/or inadequate exercise.

We conducted a case-cohort analysis in the 520,000-person European Prospective Investigation into Cancer and Nutrition study (‘EPIC-CVD’). During a median follow-up of 12.2 years, we recorded 7637 incident coronary heart disease (CHD) cases.

Compared with metabolically healthy normal weight people (reference), HRs were 2.15 (95% CI: 1.79; 2.57) for unhealthy normal weight, 2.33 (1.97; 2.76) for unhealthy overweight, and 2.54 (2.21; 2.92) for unhealthy obese people. Compared with the reference group, HRs were 1.26 (1.14; 1.40) and 1.28 (1.03; 1.58) for metabolically healthy overweight and obese people, respectively.

All else being equal, “normal” body weight results in better outcomes. However, it appears that an overweight or obese person can achieve dramatic benefits to health and longevity by changing their diet and exercise patterns even if they do not experience any significant amount of weight loss. The hazard risk for a metabolically unhealthy overweight person was almost 2 times higher than the hazard risk for a metabolically healthy overweight person, 4X larger than the 25% risk difference between a metabolically healthy overweight person and a metabolically healthy person of normal body weight.

This suggests that changes in key metabolic indicators like blood pressure should be given primacy in assessing the overall healthcare improvement of clients rather than changes in weight or BMI.

Here’s a more recent study that just came out in the European Journal of Preventive Cardiology

Joint association of physical activity and body mass index with cardiovascular risk: a nationwide population-based cross-sectional study

It asks a similar question to an equally large group :

This was the key finding:

Being either regularly or insufficiently active conferred protection compared to inactivity against all the studied risk factors within each BMI category, which was evident in a PA [physical activity] dose-response manner for diabetes and hypertension. However, regular/insufficient PA did not compensate for the negative effects of overweight/obesity, as individuals with overweight/obesity were at greater CVD risk than their peers with normal weight, irrespective of PA levels. Similar results were found overall when analysing (sic) men and women separately. 

The earlier study concludes that being overweight with healthy metabolic indicators was better than being so-called normal body weight with poor metabolic indicators. This new study concludes that the negative effects of being overweight or obese could not be compensated by physical activity of any level. 

If you take these two conclusions together, it would suggest that many overweight people with good metabolic indicators and low cardiovascular risk may in part just be lucky. If exercise can’t compensate for being overweight by itself, then some other factors must be at play, such as single nucleotide polymorphisms that affect metabolism, winning the microbiome lottery, etc. 

I wouldn’t rule out the possibility that eating a really scrupulous mostly plant-based, high-fiber diet with excess animal fat substituted with vegetable fat rather than carbohydrates could modify the microbiome and epigenetic signaling in a way that could result in a person who is overweight (but not obese) yet metabolically healthy and at a lower risk of cardiovascular disease. I just don’t think that such a diet is typical of a significant portion of the population that experiences cardiovascular disease. So, I suspect that a combination of being overweight yet metabolically healthy and at a lower risk of cardiovascular disease in the earlier study may largely be related to chance.

Do you want to know what your ideal diet is? I recently developed a tool to help people identify the ideal diet by electronically tracking certain food categories in relation to certain subjective wellness parameters. Check out the SuperOrganism™ Tracker.