Dr Guess’s Blog

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A new study just came out, and the headlines on it seem to be something along the line that “a ketogenic diet in lean individuals does not increase the risk of heart disease”. I was curious when I saw this paper, but having read through it, I don’t think the headlines reflect reality…. Why did the investigators do this study?

Zoe have a new supplement out. Is it any good? Does it work? And is it science-backed? Let’s dig in. The good It’s a mix of whole ingredients including nuts, seeds, wholegrains, legumes, vegetables and spices. None of those are going to do you any harm unless you have an allergy. These are very healthy ingredients. And in fact, there’s reasonable evidence that small differences in intake (eg small serving of nuts (30g) a day) can meaningfully improve your health.

I've written a lot on my blog about dodgy science, and dodgy nutrition products. Most of us accept that actors and sport stars are going to be on their Instagram accounts flogging bullshit like alkaline water. We tend to expect better though from people who should've had some training in the scientific method, or at least an in-depth understanding of physiology and metabolism.

If you’re concerned about high readings on your CGM, you might find these posts useful: what values are typically observed in people with normal glucose. why the usual prediabetes and diabetes cut-offs are not directly comparable to “peak” glucose. If you’re still concerned, getting an HbA1c test or even an OGTT will give you more definite insight into whether your blood glucose is officially “normal”, or maybe you might have prediabetes or even type 2 diabetes.

One of the problems with a glucocentric approach to nutrition is that the things you do to keep glucose low might be making your health worse in other ways. Reducing circulating glucose, increasing circulating fats….. One of the obvious ways that a person might choose to lower their blood glucose is to go very low carb.

Proponents of CGMs often claim that they can give people insight into foods that people can and cannot tolerate. “Eat for your unique metabolism!”. “Understand how food affects YOUR body!” - if your glucose goes up after one type of food - then you know to avoid it, right? The problem with this approach is that it assumes that glucose excursion following any given meal is directly due to whatever that person ate AT that meal. And this isn’t true.

A person’s average glucose measure (as you would get from HbA1c) does not tell you anything about the variability of glucose - how many peaks and troughs you get, and how high those peaks, and how low the troughs are. In fact, one of the potential advantages of using CGMs is that they can give you this information and more. But does it matter? Glycaemic Variability in Diabetes Let’s start with looking at the relationship between glycaemic variability (GV) in diabetes.

If you have a CGM, what kind of ranges might you expect to see? Since CGM’s are so new, we don’t know for sure, but we have some data to draw on. These studies have been done in people with normoglycaemia, and each show the baseline A1c of the people included in the study. This is helpful because right now, the most reliable evidence we have to draw on to understand the link between glycaemia and health is A1c because we have long-term data in tons of people.

I previously described how T2D and prediabetes can be diagnosed based on a fasting glucose and a 2-hour glucose (and a random glucose for T2D only). And I think because of this, people can easily freak out when they see a value of 7.0 (126mg/dL) or 7.8 (140mg/dL) or even 11.1 (120mg/dL) on their CGM devices. Like “oh people with diabetes have a glucose above 7, and this is bad, so I need to keep mine below 7 at all times”.