Hello from the Alps. The mountains are one of my favourite places, with or without snow, but especially with. The amount of snow this late in the season is amazing, and in fact too much today and visibility was poor, but didn’t stop us having a fabulous day skiing.
After last week’s blog, I received a thoughtful message from a reader, Sue, which I think is worth sharing because it highlights an important and often debated area.
Sue described how, despite being of normal weight and active, she was diagnosed with what we term “pre-diabetes” some years ago. She took a number of sensible steps—including adding strength training, as I discussed—but found that her blood sugar control only truly normalised once she reduced her carbohydrate intake. She has maintained that approach for over a decade. Interestingly, she also notes that despite eating a relatively high-fat diet, her cholesterol profile has remained favourable, and in fact improved compared to before.
There are a few really important points wrapped up in this.
Firstly, Sue is absolutely right that reducing carbohydrate intake can be a very effective way of improving glycaemic control. From a physiological perspective, that makes complete sense—if you reduce the amount of carbohydrate entering the system, particularly rapidly absorbed carbohydrate, you reduce glucose excursions and the demand on insulin and see less spikes. For some individuals, this can have a very marked effect on HbA1c and fasting glucose levels.
However, and this is where the nuance lies, it is not quite as simple as saying that “carbohydrates are the problem”. There is a very wide spectrum of carbohydrates, ranging from highly processed, rapidly absorbed sugars through to whole-food sources that are packaged with fibre, micronutrients, and have a very different metabolic impact. Foods such as vegetables, legumes, nuts, and indeed things like sweet potatoes will behave very differently in the body compared to ultra-processed carbohydrates. Lumping these together under a single heading risks oversimplifying what is, in reality, a complex area.
Even writing ‘in the body’ here is factually a bit dubious though, as secondly, and perhaps most importantly, people’s bodies respond very differently to the same foods. This is something that is becoming increasingly well recognised. Work in this area has shown that identical meals can produce very different glucose responses in different individuals, influenced by factors such as genetics, gut microbiome, body composition, and underlying insulin sensitivity.
So whilst a lower-carbohydrate approach can be extremely effective for some people, as Sue’s experience demonstrates, it is not universally required, nor is it necessarily the optimal strategy for everyone.
The same principle applies to dietary fat. There is a longstanding perception that higher fat intake will inevitably worsen cholesterol levels, but in practice this is highly variable. Many individuals can consume diets relatively rich in fat, particularly when those fats come from whole, unprocessed sources, without adverse effects on their lipid profile. In some cases, lipid markers may even improve, particularly if overall metabolic health improves alongside it.
What this really speaks to is the importance of moving away from rigid dietary “rules” and towards a more personalised approach. What matters most is not the label of the diet, but the metabolic response of the individual.
In practical terms, that means using objective markers such as HbA1c, fasting glucose, and lipid profiles to guide decisions, rather than relying purely on generalised advice.
Sue also makes an excellent point about the term “pre-diabetes”. It is, as she says, really a continuum rather than a fixed state. And importantly, it is often reversible—sometimes with relatively modest but targeted changes.
So What Should You Take From This?
- Reducing carbohydrate intake can be highly effective for improving blood sugar control in some individuals.
- The type and quality of carbohydrate matters just as much as the quantity
- Dietary fat does not have a uniform effect on cholesterol, it varies significantly between individuals
- The most useful approach is to measure, adjust, and personalise, rather than follow a one-size-fits-all strategy
Sue’s experience is a very good example of something I see regularly in clinic: two people can look very similar on the surface, yet respond very differently to the same intervention. This brings us back to the central theme of the last two week’s blog; much of metabolic health sits beneath the surface, and improving it often requires a personalised, rather than prescriptive, approach.
Now I’m going to end with a carbohydrate confession. Yesterday on the drive down to the Alps we detoured to a big supermarket to get some sushi for my daughter’s lunch; she has coeliac disease so France can be a bit challenging. We had planned on getting the rest of us a nice baguette sandwich, but tried two places and both sold out. We needed to get on with the drive, so went with the only option around – McDonalds. I was trying to remember the last time I had one, it’s got to be a few years. I just had a BigMac and a coffee. The BigMac was much smaller than I remembered, but was very tasty as these things are designed to be. I wolfed it down feeling somewhat guilty, then was hungry again an hour later! I guess I’ve reinforced the simple carbohydrate lesson and it will likely be another few years before I’m forced into that position again!