Interactive risk curves for the burden of proof inclusion. https://vizhub.healthdata.org/burden-of-proof/

Notes:

One issue involves the assumption of log-linearity, which requires that the hazard ratio for a fixed increment of red meat consumption (for example, 100 g d−1) remains constant across all levels of intake (an increase in consumption from 0 to 100 g d−1 would have the same effect as an increase from 200 to 300 g d−1 ). Yet evidence indicates that the dose–response relationship for many risk factors attenuates at higher doses17,18 (not log linear).

Another notable issue is that meta-analyses attempting to synthesize findings from cohort studies typically do not account for between-study heterogeneity, which can be a prominent source of bias in epidemiological meta-analyses

In most studies (45 of 55), RRs were adjusted for major confounders including age, sex and smoking

This really should include sugar consumption.

The fact there is a weak association between type 2 diabetes and red meat consumption should tell you everything you need to know about healthy user bias in a nutshell. Type 2 Diabetes is a condition of carbohydrate intolerance / overload. Red meat does not increase blood glucose to any meaningful degree. Red meat is not a independent risk factor for T2D. However, the population who eats higher levels of red meat typically does so in the context of a high carbohydrate diet (burgers and fries for example), which is a massive causal factor for T2D.

A key finding of our analysis is that there is substantial between-study heterogeneity and uncertainty for all six risk–outcome pairs included. This may partly reflect the high degree of heterogeneity often present in data sources used for dietary analysis, which typically comprise observational studies. This heterogeneity limited the sensitivity of our analysis to identify clear—and potentially clinically important—relationships between intake and disease end points. Although visual inspection of the mean risk functions suggests a positive (harmful) relationship between unprocessed red meat intake and colorectal cancer, type 2 diabetes, IHD, ischemic stroke and breast cancer and a negative (protective) relationship with hemorrhagic stroke, the large degree of heterogeneity present, coupled with the moderate mean effects, generated wide UIs for the mean risk functions.