One dial, three systems

Sleep eight hours, eat reasonably well, exercise when life allows — and still wake up tired, carry weight that refuses to shift, and find recovery slower than it was a decade ago. For many people in their forties, fifties and sixties, these feel like separate problems requiring separate fixes. They are not.

Blood glucose is the single upstream variable connecting all three. Rather than a number that only matters in a clinic, it functions as a continuous control signal: simultaneously routing fuel into cells, directing the immune system's inflammatory tone, and deciding whether the body burns fat or locks it away. Turn that signal erratic, and the downstream effects show up as fatigue, stubborn weight and sluggish repair — all at once.

This is the territory that Professor Paul Lee maps under the Chemistry pillar of Regeneration by Design. Stable blood sugar, he argues, is a foundation of the body's internal environment — and destabilising it sets off a chain reaction that touches almost every system.

The article unpacks four converging mechanisms through which blood sugar exerts that influence: fuel routing and fat storage, the inflammation cycle, mitochondrial energy production, and the glycation of tissues over time.

How a carbohydrate meal becomes stored fat

Think of glucose arriving in the bloodstream like fuel being pumped into an engine running at a fixed speed. The body can burn some of it immediately — converting it to ATP, the cellular energy currency that powers muscles, organs and brain. What the engine cannot use right away is shunted into short-term storage: glycogen packed into liver and muscle cells, ready for the next burst of demand. So far, so sensible.

The problem begins when the tank overflows. Glycogen stores are finite, and once they are full, the body has nowhere obvious to put the remaining glucose. At this point, the liver steps in and runs a conversion process called de novo lipogenesis — essentially manufacturing triglycerides from surplus sugar. Those triglycerides are then exported and deposited in adipocytes: the long-term storage tanks. A carbohydrate meal has become body fat.

Insulin is the switch that manages all of this. Its primary role is to signal cells to absorb circulating glucose — but it has a second, less discussed effect: it actively suppresses fat oxidation. While insulin is elevated, the body cannot draw on existing fat stores for fuel. The exit door is locked.

This means that repeated glucose spikes — breakfast to snack to lunch — can hold insulin elevated for much of the day, tipping the body into a near-continuous storage state. Calorie intent becomes almost beside the point: the hormonal signal is pointing firmly in one direction. As the next section shows, those expanding fat stores then generate a problem of their own.

How fat cells ignite the inflammation cycle

The expanding fat cells described in the previous section do not simply sit inert. As adipocytes fill beyond their oxygen-supply capacity, they begin to experience localised cellular stress — and a stressed fat cell is not a quiet one. It releases a cascade of pro-inflammatory signalling molecules, including cytokines such as TNF-alpha and interleukin-6, which are intended to recruit immune cells and attempt tissue repair.

The problem is that these cytokines do not stay local. Once in circulation, they interfere with insulin-receptor signalling on muscle and liver cells — the very cells responsible for clearing glucose from the bloodstream. With those receptors partially blocked, glucose uptake slows, blood sugar remains elevated for longer, and the pancreas responds by secreting still more insulin. More insulin means more fat storage, which means more expanded adipocytes, which means more cytokine release. The loop is now closed and self-reinforcing.

What makes this cycle particularly insidious is that it produces no acute signal. There is no pain, no sudden shift — only a background hum of low-grade inflammation that researchers have labelled 'inflammaging'. Unlike the short, sharp immune response to an injury or infection, this variety is chronic and self-sustaining, compounding silently over years. Its first noticeable effects tend to arrive as fatigue that sleep does not fix, weight that resists effort, and recovery that feels disproportionately slow — symptoms that may appear long after the cycle is well established.

Blood-sugar stability matters structurally precisely for this reason: keeping adipocytes from overfilling in the first place may interrupt the cycle before it has a chance to build momentum.

The mitochondrial toll: why blood sugar spikes erode energy

Burning glucose for energy is not a clean process. Inside every cell, mitochondria act as combustion chambers — extracting ATP from fuel passing through the electron transport chain. Under normal conditions, a small amount of reactive oxygen species (ROS) leaks from this process: molecular exhaust that the cell's antioxidant systems can neutralise without difficulty. A sharp glucose spike changes the equation. Flood the chain with more fuel than it can process and ROS production surges beyond what the cell can contain. The exhaust overwhelms the extractor.

Repeat that scenario several times a day — as tends to happen when meals are carbohydrate-heavy and insulin is frequently elevated — and the accumulated damage becomes measurable. Mitochondrial DNA and the proteins embedded in the electron transport chain are particularly vulnerable to oxidative stress; Xu et al., writing in Nature in 2025, link this mitochondrial dysfunction directly to systemic inflammation and accelerated biological ageing. Sivitz and Yorek's earlier review in Diabetes & Metabolism traces the same pathway in the context of metabolic disease, noting qualitative and functional perturbations that affect ATP output.

The consequence the Regen PhD audience knows in practice is not a laboratory readout — it is the afternoon energy trough that coffee cannot fix, the brain fog that follows a high-carbohydrate lunch, or the exercise session that leaves the body depleted for two days rather than one. These are the signatures of eroded metabolic flexibility: the capacity to switch efficiently between glucose and fat as circumstances demand. That capacity is not fixed. It responds to training, to nutrient timing and — as Professor Paul Lee's Chemistry pillar framework makes clear — to the internal environment that blood-sugar habits create day by day. The mitochondria are where the body's chemical environment and its physical energy output converge.

Glycation: where blood sugar shows up in ageing tissue

Skin that has lost its spring, arteries that no longer flex readily, joints that feel stiffer than they did a decade ago — these changes share a molecular culprit that operates separately from the inflammation cycle already described. It is called glycation, and it is blood sugar's most visible calling card.

When glucose circulates at repeatedly elevated levels, it attaches non-enzymatically to proteins and fats throughout the body — a slow-motion version of what happens when sugars caramelise under heat. The resulting compounds are Advanced Glycation End Products, or AGEs. Unlike a short-lived glucose spike, AGEs accumulate permanently: once formed, they are not easily cleared. Over years, they cross-link structural proteins such as collagen and elastin, stiffening connective tissue, blood vessel walls and skin progressively — a direct biochemical pathway from blood-sugar habits to measurable tissue ageing, documented by Prasad et al. (PMC, 2017) and Uribarri et al. (ScienceDirect, 2015).

AGEs also bind to RAGE receptors on immune and vascular cells, sustaining a low-grade inflammatory signal independently of circulating insulin levels — meaning the damage continues even when glucose has returned to range.

Diet adds a practical lever. Food cooked at high temperatures — grilled, fried, roasted — arrives pre-loaded with exogenous AGEs that compound the body's internally produced burden. Choosing gentler methods such as steaming, poaching or slow-cooking may help moderate that cumulative load. It is a small daily adjustment with long-term consequence: as the Time pillar in Regeneration by Design emphasises, damage of this kind does not plateau — it compounds. That is the argument for attending to blood-sugar stability early, rather than waiting for the signs to become apparent.

Practical levers and how to see where your dial is set

Blood sugar is not fate. Unlike genetic starting points or the passage of time, it responds — measurably, and relatively quickly — to a handful of consistent decisions. Professor Paul Lee's Chemistry pillar, developed across Regeneration by Design and the 2026 follow-up Practical Regeneration, identifies four levers that consistently move this dial.

Dietary fibre slows glucose absorption into the bloodstream, blunting the post-meal surge that overloads the mitochondrial chain and pushes insulin output higher. Prioritising vegetables, legumes and whole grains — and eating them before refined carbohydrates rather than alongside them — may reduce peak excursions meaningfully. Polyphenols, present in berries, dark chocolate, green tea and extra-virgin olive oil, appear to modulate glucose uptake and support insulin sensitivity through multiple pathways. Healthy fats — from avocado, nuts, oily fish and olive oil — slow gastric emptying, softening carbohydrates' glycaemic impact and extending satiety. Omega-3 fatty acids, particularly from marine sources such as salmon and mackerel, are among the most consistently studied dietary tools for calming the systemic inflammation that blood-sugar dysregulation produces downstream. Practical Regeneration names all four specifically, alongside curcumin and gingerols, as the Chemistry-pillar foundation for metabolic and inflammatory control.

Knowing what to eat is one thing; knowing where your dial currently sits is another. Three markers tell most of the story: HOMA-IR, which quantifies insulin resistance directly; hs-CRP, a sensitive index of systemic inflammation; and ApoB, which captures atherogenic particle burden — cardiovascular risk that elevated blood sugar accelerates through AGE cross-linking and vascular stiffening. Standard NHS panels rarely include all three together. The Regen PhD Blood Panel is designed to provide exactly this baseline picture of how efficiently the body is managing its internal chemistry — a concrete starting point rather than an abstract score. For anyone considering significant dietary changes or acting on blood-test results, consultation with a qualified healthcare professional is the appropriate first step.

1. [1] Insulin resistance — Wikipedia. https://en.wikipedia.org/?curid=54448 https://en.wikipedia.org/?curid=54448