Does meat cause diabetes? Obviously not. Yet some have been trying to prove it for years without success.

Here we go again. Yet another study was released a few days ago, which tries to demonstrate the association between meat consumption and the onset of type 2 diabetes. Among the authors is Walter C. Willett, and the modus operandi is always the same: publish studies of low scientific quality on the link between meat and diabetes when systematic reviews and clinical studies of the utmost scientific rigour have already amply demonstrated the opposite.

Research on the topic has reached its final stage, demonstrating that meat does not increase blood sugar, insulin resistance, inflammation and the risk of type 2 diabetes. In fact, on the contrary, when people are encouraged to eliminate cereals, starches and sugars and eat more red meat, it can reverse type 2 diabetes and make its symptoms disappear.

The crusade against meat doesn’t stop

Persevering with an unwavering, decades-old pro-veg ideology and backed by financial interests from multinationals producing hyper-processed vegan foods, Willett is tireless in his attack on meat. Despite the numerous debunkings it has suffered, his new study insists on proving a link between meat and diabetes at all costs. On the surface, it would appear to be a valuable study, being a meta-analysis published in the prestigious journal The Lancet Diabetes and Endocrinology; in reality, it has strong limitations, missing data and no causal link, as several experts in scientific research are pointing out.

“This research is a meta-analysis that inserts cohorts from scratch without a documented clinical history behind them,” explains Professor Giuseppe Pulina, President Emeritus of the Association for Animal Science and Production, Full Professor of Ethics and Sustainability of Livestock Farming at the Department of Agriculture from the University of Sassari and President of Carni Sostenibili: “Being cohort studies, they do not provide causation and therefore a direct causality cannot be established between meat consumption and the onset of type 2 diabetes. In fact, the associations observed may be influenced by confounding factors that have not been fully controlled.”

An inconsistent study, to say the least

Type 2 diabetes belongs to the pathological picture of the so-called metabolic syndrome, which has multiple and differentiated aetiology, characterised by the simultaneous presence of multiple risk factors such as abdominal obesity, hypertension and high fasting blood sugar. Given the complex and multifactorial aetiology, which includes genetic, environmental and behavioural factors, with obesity and sedentary lifestyle among the main risk factors, it is impossible to identify a dietary cause easily from 10-year follow-up questionnaires, which are not completely accurate.

Meat consumption was measured through self-reported dietary questionnaires, which is the least reliable way to collect data because participants may have reported their meat consumption and other dietary behaviours inaccurately or incorrectly, introducing a self-selection bias, overestimating or underestimating the consumption of certain foods.

Additionally, meat quality and cooking methods may influence the risk of type 2 diabetes, but these variables have not been fully explored. For example, given that the only novelty of this research is that it also included chicken meat besides red and hyper-processed meat, no difference is made between breaded fried chicken and roast chicken.

Finally, the study population does not represent the entire global population, so the results cannot be generalised. This is why they must be interpreted with caution; further studies are needed to confirm the observed associations and establish a clear causal relationship.