Creative Touch Permanent Makeup and Aesthetics

High sugar and ultra-processed food intake describes a dietary pattern characterised by high consumption of NOVA Group 4 ultra-processed foods – industrially manufactured products formulated with additives, flavourings, and engineered macronutrient profiles not present in home cooking – alongside high free sugar intake from refined carbohydrates and sweetened beverages. This dietary pattern is now the subject of substantial epidemiological evidence: a 2025 meta-analysis of over 100 prospective cohort studies across 93 countries found associations between high UPF intake and elevated risk of obesity, type 2 diabetes, cardiovascular disease, cancer, and all-cause mortality, with risk magnitudes comparable – in the opposite direction – to the protective effects of Mediterranean diets. The biological harms operate through at least four distinct mechanisms: ileal brake bypass and attenuated satiety signalling; endogenous and exogenous AGE formation and the RAGE/ NF-κB inflammatory loop; gut microbiome dysbiosis and LPS-mediated systemic inflammation; and hypothalamic inflammation driving leptin resistance. Each mechanism has direct consequences for skin quality and treatment responsiveness, making dietary pattern one of the most underexamined variables in aesthetics consultation. gov.uk

Few dietary questions have generated as much scientific debate and public confusion as the health consequences of processed food. Part of the difficulty has been definitional: “processed” covers everything from pasteurised milk to reconstituted meat products, and treating these as equivalent obscures the very different biological consequences of different processing levels. The NOVA classification system resolves this by providing a processing-based taxonomy that has now been validated across decades of epidemiological research and – as of April 2025 – formally recognised by SACN (the UK’s Scientific Advisory Committee on Nutrition) as the only food classification system meeting criteria for use in UK dietary assessment. gov.uk

The NOVA Classification: A Practical Framework

NOVA classifies foods into four groups based on the extent and purpose of processing, not nutritional composition: ^[1]

Group 1 – Unprocessed or minimally processed foods: Whole foods in their natural state or with minimal alteration (washing, cutting, freezing, pasteurising). Fruit, vegetables, meat, fish, eggs, plain dairy, legumes, grains. These form the foundation of health-supporting dietary patterns.

Group 2 – Processed culinary ingredients: Substances extracted from Group 1 foods or from nature and used in cooking – oils, butter, flour, sugar, salt. Not typically eaten alone; used in preparation of Group 1 foods.

Group 3 – Processed foods: Group 1 foods preserved or transformed by simple processes – tinned vegetables, cured meats, artisan cheese, freshly baked bread. Recognisable as the original food; short ingredient lists; no industrial additives.

Group 4 – Ultra-processed foods (UPFs): Industrial formulations containing ingredients not used in home cooking – emulsifiers, stabilisers, flavour enhancers, artificial sweeteners, hydrogenated fats, modified starches – alongside engineered macronutrient profiles designed for hyperpalatability, extended shelf life, and convenience. Breakfast cereals, soft drinks, packaged snacks, reconstituted meat products, flavoured yoghurts, fast food, most commercially baked goods.

The NOVA framework’s value is not that processing is inherently harmful – Group 3 processed foods show no consistent adverse health associations – but that Group 4 UPFs represent a categorically different food environment: products engineered to maximise consumption rather than nutrition. ^[1]

The macronutrient profile of UPFs – characteristically high in both refined carbohydrates and processed fats delivered simultaneously – is worth noting as a distinct metabolic concern beyond their additive load and nutritional displacement. The Randle Cycle describes the reciprocal competition between glucose and fatty acid oxidation at the cellular level: when both substrates are chronically elevated together, neither is handled cleanly, generating lipid intermediates – diacylglycerol (DAG) and ceramides – that impair insulin receptor signalling and drive the insulin resistance trajectory. Clean macronutrient separation, characteristic of whole food dietary patterns regardless of their specific macronutrient ratio, avoids this metabolic impasse. The cellular mechanism behind why the fat-sugar combination is specifically harmful – and why both low-fat/high-carbohydrate and high-fat/low-carbohydrate whole food patterns outperform the UPF macronutrient profile metabolically – is developed in the Randle Cycle entity.

Proximal Absorption and the Ileal Brake Bypass

The first and most immediately relevant mechanism for appetite regulation is the location at which UPFs are digested. Refined carbohydrates – the macronutrient backbone of most UPFs – are rapidly digested and absorbed in the duodenum and proximal jejunum. Little to no substrate reaches the ileum, where L-cells would normally detect unabsorbed nutrients and release GLP-1 and PYY in response. The satiety signal the ileal brake is designed to produce simply does not occur, or occurs at substantially attenuated levels, after a UPF-dominant meal.

This is mechanistically distinct from the caloric content of the meal. A meal of equivalent calories from protein and fat delivers unabsorbed substrate to the ileum, activating robust L-cell GLP-1 and PYY secretion and producing a satiety window of two to four hours. The same calories from rapidly absorbed refined carbohydrate clear the proximal intestine without triggering this response – appetite returns earlier, the next meal arrives sooner, and total caloric intake tends to increase not because of failure of willpower but because the hormonal architecture for satiety was never engaged. The ileal brake mechanism and macronutrient specificity are detailed in the Ileal Brake entity; the practical consequence here is that UPF-dominant dietary patterns structurally suppress the body’s endogenous satiety system at the point of meal composition.

This same proximal absorption also produces the glycaemic consequences explored in the next section. Rapid glucose delivery to the portal circulation from refined carbohydrates generates a sharp postprandial glucose spike, followed by an insulin-mediated correction that can overshoot into reactive hypoglycaemia – driving the hunger and energy dip that characterises the two-to-three-hour post-UPF-meal period and reinforces the cycle of seeking the next reward. The sustained hyperinsulinaemia produced by habitual high-glycaemic intake also activates the IGF-1/androgen/ sebum axis in the pilosebaceous unit, with direct consequences for sebum production and acne pathogenesis; this is covered in the Blood Sugar and Skin entity.

AGE Formation: Endogenous and Exogenous Pathways

Sustained high sugar and refined carbohydrate intake produces chronic low-level hyperglycaemia – even below the diagnostic threshold for type 2 diabetes – that drives the endogenous formation of advanced glycation end-products (AGEs). The Maillard reaction between free glucose and the amino groups of long-lived proteins – collagen, elastin, lens crystallins – produces progressively cross-linked protein aggregates that resist enzymatic degradation, accumulating in tissue over years and decades. In skin, this manifests as the progressive cross-linking and stiffening of dermal collagen that contributes to loss of elasticity, impaired wound healing, and the yellowing of glycated skin visible under Wood’s lamp examination. Tight glycaemic control reduces the rate of endogenous AGE formation – confirming this process is modifiable through dietary change rather than being purely a function of chronological age – though prospective skin-outcome RCTs in non-diabetic populations remain limited.

A second AGE pathway is exogenous: dietary AGEs (dAGEs) formed during high-temperature dry-heat cooking – grilling, frying, roasting – are partially absorbed (approximately 10–30%) and measurably raise circulating AGE markers. RCT evidence confirms that low-dAGE diets reduce circulating AGE levels and some oxidative stress markers, particularly in diabetic populations. Whether this translates to measurable skin outcomes in healthy individuals has not been demonstrated in clinical trials; the skin relevance of dAGEs remains a mechanistically plausible but clinically unproven extension of the endogenous AGE evidence. The most actionable aspect of the evidence is the cooking method distinction: moist-heat methods (steaming, poaching, slow-cooking) produce substantially fewer dAGEs than equivalent dry-heat preparation, providing a low-friction modification for clients already motivated to reduce their AGE burden.

Both AGE pathways converge on the same downstream mechanism: RAGE activation. AGEs bind to RAGE (receptor for advanced glycation end-products), which signals through NF-κB to upregulate pro-inflammatory cytokine production – IL-6, TNF-α, MCP-1. This creates a self-amplifying loop: high sugar intake drives AGE formation, AGEs activate RAGE, RAGE activates NF-κB, NF-κB drives systemic inflammation, and that inflammation further impairs the glycaemic regulation that would limit further AGE formation. The full AGE/RAGE/NF-κB mechanism is developed in the Glycation entity; the key point here is that the dietary pattern drives the process from the upstream end. The downstream consequences of this glycaemic exposure for skin collagen structure – including the relevance of postprandial glucose variability independent of fasting glucose, and the disproportionate glycation burden from dietary fructose – are developed in the Blood Sugar and Skin entity.

The Gut Microbiome: Dysbiosis, Zonulin, and LPS Translocation

A mechanistic pathway that receives less attention in consumer health content but is supported by substantial research is the gut microbiome consequence of high UPF intake. The harm here is driven less by fibre absence than by specific UPF additives – emulsifiers (carboxymethylcellulose, polysorbate 80, carrageenan) and artificial sweeteners – that directly disrupt the gut mucus layer and alter microbial composition. These additives deplete Akkermansia muciniphila and Faecalibacterium prausnitzii – species with established roles in maintaining intestinal barrier integrity – whilst promoting a pro-inflammatory microbial environment. The result is dysbiosis: a shift towards gram-negative bacteria whose cell walls contain lipopolysaccharide (LPS).

The butyrate picture is worth clarifying for precision. Butyrate – the short-chain fatty acid that primarily fuels colonocytes and supports barrier integrity – can be derived from two distinct dietary routes: microbial fermentation of dietary fibre in the colon, and directly from ruminant dairy fat (butter, cream, aged cheese), which contains pre-formed butyrate that does not require microbial production. The harm of UPFs is therefore not simply that they displace fibre; it is that their additive load actively disrupts the microbial ecosystem whilst simultaneously displacing whole food sources – whether plant or animal – that support gut barrier function through various routes.

Dysbiosis and direct additive-mediated barrier disruption both trigger upregulation of zonulin – a protein that regulates tight junction permeability in the intestinal epithelium. Elevated zonulin loosens tight junctions, increasing intestinal permeability – the mechanism commonly described as “leaky gut.” Through this permeable barrier, LPS fragments translocate into portal and systemic circulation – metabolic endotoxaemia.

The systemic consequence is continuous, low-grade immune activation. LPS activates toll-like receptor 4 (TLR4) on macrophages and dendritic cells, triggering NF-κB-mediated cytokine production – the same inflammatory cascade driven by RAGE, now activated through an entirely separate upstream pathway. Metabolic endotoxaemia from UPF-driven gut dysbiosis is therefore an independent contributor to the chronic low-grade systemic inflammation that defines inflammageing – one that operates continuously between meals. This inflammatory baseline degrades skin quality through the same mechanisms as the RAGE/NF-κB pathway: increased MMP activity, suppressed fibroblast collagen synthesis, and accelerated cellular senescence via the SASP.

Hypothalamic Inflammation and Leptin Resistance

The gut-derived LPS and the systemic cytokines elevated by UPF-driven inflammation do not remain peripheral. They cross the blood-brain barrier and activate microglial cells in the hypothalamus – driving hypothalamic inflammation through TNF-α, IL-6, and IL-1β that directly impair leptin receptor signalling in arcuate neurons. This is the dietary mechanism that underlies the leptin resistance established in the Leptin entity: it is not primarily a consequence of obesity itself but of the inflammatory dietary pattern that frequently produces obesity. The implication is that improving dietary pattern – reducing UPF intake and restoring microbiome diversity – may improve leptin sensitivity through hypothalamic inflammation reduction independently of weight change, though evidence for this in human clinical trials remains an active area of research. nature

The Skin Consequences: A Synthesis

The four mechanisms above converge on skin quality through overlapping but distinct pathways:

Collagen structure: Endogenous AGE cross-linking progressively stiffens and degrades dermal collagen. Fibroblast MMP upregulation from NF-κB activation accelerates extracellular matrix degradation. The skin of someone with a sustained high-sugar dietary pattern accumulates structural collagen damage that aesthetic treatments must work against rather than with.

Inflammatory baseline: Metabolic endotoxaemia and RAGE/NF-κB activation maintain a systemic inflammatory state that impairs skin barrier function, reduces epidermal turnover, and – through the SASP – amplifies local senescent cell burden in the dermis. This is the inflammageing mechanism manifesting in skin; the dietary pattern is its upstream driver.

Treatment responsiveness: Collagen-stimulating treatments – RF microneedling, PNRS, polynucleotides – depend on fibroblast responsiveness and adequate substrate availability for new collagen synthesis. A client in a state of chronic NF-κB activation, elevated MMPs, and glycated existing collagen presents a compromised biological environment for these treatments. Understanding dietary pattern as a treatment responsiveness variable is not a peripheral consideration – it is mechanistically central.

The Teaspoon Equivalents Framework

Communicating the sugar content of foods in teaspoon equivalents – a framework developed and used in clinical practice by Dr David Unwin – makes the glycaemic load of familiar foods viscerally legible in a way that grams of carbohydrate or glycaemic index scores do not. journalofmetabolichealth A bowl of cornflakes is approximately 9 teaspoons of sugar-equivalent; a medium portion of white rice approximately 10; a can of cola approximately 9. Against this, a full English breakfast with eggs, bacon, and grilled tomatoes is approximately 1–2 teaspoons.

This framework does not require clients to count carbohydrates or track macros – it requires only a mental image of teaspoons to evaluate a meal. In an aesthetics and weight management consultation context, it is one of the most effective tools for helping clients see the glycaemic consequences of their dietary pattern without triggering the shame or defensiveness that calorie-counting often does. It also provides a concrete metric for the dietary change most likely to reduce both endogenous AGE formation and ileal brake bypass simultaneously.