Missing breakfast raises risk of heart disease, diabetes & obesity: or does it?

The Executive Summary

If you fare better with breakfast enjoy it. If you don’t – don’t!

If you want more…

The Story

The UK woke up this morning (31 January 2017) to the headline” DON’T skip breakfast! Official advice warns that missing out on a morning meal raises the risk of obesity, heart disease and diabetes”. The US angle was: “For heart health, it’s not just what you eat, but when” (CBS link).

The media headlines came from this article: “Meal Timing and Frequency: Implications for Cardiovascular Disease Prevention: A Scientific Statement From the American Heart Association”. You can download the PDF and read the full 27 pages if you like. The lead author was Dr. Marie-Pierre St-Onge and she can be seen talking about the review in a very short video on the CBS link above.

The conflicts of interest

If you don’t fancy the full document, the American Heart Association short statement can be seen here. I’d like to draw your attention to this part of the statement:

“Several studies have shown the benefit of eating breakfast every morning… But breakfast studies also have recently come under fire when media reports showed Kellogg and General Mills, the two largest U.S. cereal manufacturers according to Hoovers, funded some of the research. This could have skewed positive results about the benefit of breakfast.”

No kidding! I’ve previously covered a couple of gems when cereal companies try to encourage consumption of breakfast – because – what do most people eat for breakfast? Yes – cereal! You may enjoy this and this.

The evidence

The 27 page report looks at meal timing and meal frequency – not just breakfast. As breakfast got the headlines, let’s just look at the claims made about skipping breakfast (defined as “not eating anything before lunch”) and i) obesity, ii) heart disease and iii) diabetes.

i) The evidence for ‘skipping breakfast and obesity’ came from a few studies, which spotted that people who skip breakfast appear more likely to be obese. But – assuming that there is such a relationship – what’s the direction of causation? Does skipping breakfast make you obese? Or Do obese people tend to skip breakfast?!

ii) The evidence for ‘skipping breakfast and diabetes’ was based on three, what we call “population studies” (this is where personal details are recorded when large numbers of people are recruited to a study. The people are then followed over many years to see which conditions they develop and then researchers can observe patterns like “smokers went on to develop lung cancer” etc). Again – a relationship was observed between skipping breakfast and being diagnosed with type 2 diabetes.

This one was more interesting, but it would still be possible that obese people would be more likely to skip breakfast and obese people would be more likely to develop type 2 diabetes. This is what is known as a “confounder” – something else going on that explains the relationship instead of the one being claimed.

A book out at the start of this month “Breakfast is a dangerous meal” by Professor Terence Kealey was interesting in this context. Kealey is a Type 2 diabetic and he noticed breakfast adversely affected his blood glucose control more than meals later in the day and so he stopped eating breakfast. In his book, he presents some interesting trials supporting his observations. His direction of causation was clearly the other way round. He may not be alone.

iii) The evidence for ‘skipping breakfast and heart disease’ was based on just two population studies – one of American men and the other of Japanese men and women. The Japanese study didn’t even find a relationship with never eating breakfast and heart disease, but it did find one for strokes (which was barely significant). The American study claimed a relationship between eating breakfast and having lower heart disease. However, the paper also admitted that this relationship was “mediated by body mass index, hypertension, hypercholesterolemia, and diabetes mellitus” which is academic speak for “it fell away when you take all those things into account.” (And indeed it did completely fall away/disappear – I checked the full paper).

Other things about breakfast avoiders

The naughty American study just above, which should have declared results after adjusting for other factors, shared some interesting characteristics of people who avoid breakfast. Breakfast avoiders are more likely to: be smokers; work full time; be less physically active; and drink more alcohol. I’m getting a picture of a night owl, working late at their desk, eating, drinking and smoking into the early hours and another picture of an early bird bouncing out of bed to walk the dog, followed by a hearty bacon and eggs before checking emails.

Sweeping generalisations – but then so is “skipping breakfast will give you obesity, diabetes and heart disease”! Maybe there’s something inherently healthy about the lifestyle of breakfast eaters and breakfast has nothing to do with it?

The takeaway message

If you fare better with breakfast enjoy it. If you don’t – don’t!

By fare better, I mean function better in the morning/generally throughout the day, feel less in need of bad food later on, find it helps with your own weight and health goals etc. If breakfast doesn’t work for you – as it doesn’t for Prof. Kealey – then don’t have it. And if you do have breakfast – you’d be well advised to avoid the sugary cereals promoted by the companies behind many of the ‘breakfast is good for you’ studies out there.

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