Yes, We Have Long-Term Data on Diets—Here’s the Proof You Need To Know

So… Do We Really Have No Long-Term Data on Diets?

Claim: “We really don’t have any long-term data on any dietary pattern” 

In response to Steven Bartlett's question about whether it’s possible to live a long time on the carnivore diet without supplementation, Ede responds with this claim that we don’t have long-term data on any dietary pattern. 

This claim is misleading and incorrect. While no studies have followed an individual for their entire lifetime, several major long-term studies record and track dietary patterns and health outcomes over decades.

In fact, several cohort studies were designed to provide long-term information on dietary patterns. These include the Nurses Health Study and the Health Professionals Follow-Up Study, which began in the 1970s and 1980s and have been running ever since, tracking dietary habits and their associations with health outcomes such as heart disease, type 2 diabetes, and cancer risk. This data gets analyzed by very talented and experienced researchers, especially epidemiologists, to provide us with a wealth of information on what dietary patterns can support human health and longevity. 

A study published in Nature Food in 2023 used data from the UK Biobank, a large prospective cohort, to analyze the impact of sustained dietary changes on life expectancy. The researchers found that changing from unhealthy dietary patterns to healthier ones, such as those recommended by the Eatwell Guide, could increase life expectancy by up to 8.9 years for 40-year-old males and 8.6 years for females.

But Is This Data Good Quality at All?

Ede, like others, may argue that these types of studies are unreliable and don’t provide long-term quality data, because they mostly use food frequency questionnaires to measure what people eat over time. These questionnaires ask what people ate over a specified time frame, which could be up to a year, so people claim they might not be accurate as it relies of memory. 

But it’s not that simple. These methods are widely validated and refined by top nutrition scientists, hence why they are widely used in research, as Dr Matthew Nagra covers in his recent video:

We also have randomised controlled trials, which are a higher-quality type of evidence, that have examined dietary patterns over 4 to 7 years. One of these studies, which looks at the Mediterranean diet, found it to lower cardiovascular risk. “And cardiovascular disease is a chronic disease that develops over a very long period of time” explains Dr Nagra. 

While we don’t have long-term data on the carnivore diet, we do have data on the different elements long term, such as excessive processed and red meat consumption increasing the risk of certain cancers, and increased risk of mortality without adequate fruit and vegetable consumption. 

🔗 Want to understand this in more depth?

Chris from Viva Longevity explains the reliability of nutrition science in this 

We have contacted Steven Bartlett and are awaiting a response.