Insulin Resistance and Adipose Tissue
Insulin resistance is often the body’s response to chronic energy surplus and inflammation — not a permanent fault, but reversible through sleep, movement, and steady rhythm.
Insulin resistance[G] is not always a “defect” — often it is the body’s response to chronic energy surplus, inflammation, or a disordered rhythm. Adipose tissue is not a passive storage depot but an active hormonal and immune organ; its enlarged cells can drive inflammation and insulin resistance. Weight loss happens mostly through the emptying of fat cells, not their disappearance. Insulin resistance[G] is not a permanent state: it can be reversed through lifestyle, sleep, stress reduction, and microbiota[G] stability.
Insulin resistance: defect or biological response?
Insulin resistance is often treated as a disease with a single cause, when in fact it usually arises from a combination of factors. Persistent energy surplus, poor sleep, low physical activity, chronic stress, and low-grade inflammation can all contribute to cells becoming less responsive to insulin. This does not happen overnight; it develops slowly over many years.
In certain situations insulin resistance[G] can also be a transient adaptation. During illness or acute stress, the body temporarily modifies insulin sensitivity[G] so that the brain and vital organs continue to receive energy — short-term this is normal. The sustained form is different: the modern lifestyle — constant snacking, late-night eating, low physical activity, sleep deprivation — turns this transient state into a chronic one.
Adipose tissue as a hormonal organ – cell size, inflammation, and visceral fat
The role of adipose tissue here is crucial. The fat cell is not a passive storage depot but an active endocrine and immune organ. When fat cells grow too large (adipocyte hypertrophy), they produce inflammatory signaling molecules, worsen insulin sensitivity[G], and further amplify metabolic dysfunction. For metabolic health, then, body weight alone is not enough — fat-cell size and function also matter.
Weight loss in reality mostly means not the disappearance of fat cells but their emptying. In adulthood the number of fat cells is relatively stable (about ~10% annual turnover), and change occurs mainly through the filling of existing fat cells (hypertrophy). In sustained or severe obesity, however, the formation of new fat cells (adipogenic hyperplasia) can also begin, which increases the tendency to regain weight after fat loss. The goal of weight loss is therefore not to reduce the number on the scale but to reduce the size of fat cells and improve the hormonal environment.
Clinically, it is important to distinguish between fat surrounding the organs (visceral) and fat under the skin (subcutaneous). Abdominal, visceral fat is more strongly linked to inflammation and insulin resistance — partly because, through portal circulation, the liver is directly exposed to free fatty acids and inflammatory adipokines from visceral fat, which drives hepatic insulin resistance. This is why we use the waist-to-hip ratio or waist circumference to estimate metabolic risk. A patient with a normal BMI but high abdominal fat can be at greater metabolic risk than someone with higher body weight but low visceral fat.
A reversible process – rhythm, microbiota, and metabolic restoration
The microbiota[G] is also part of this system. In dysbiosis[G], LPS[G] (lipopolysaccharide[G]) released from the wall of gut bacteria crosses a leaky gut barrier and enters the circulation, triggering low-grade systemic inflammation — this is known as metabolic endotoxemia (increased gut permeability[G] as a mechanism is documented; as a stand-alone diagnosis, however, “leaky gut syndrome” is not a validated clinical entity and there is no standardized test for it). This directly impairs the insulin sensitivity[G] of fat cells and the liver [124]. Fiber intake, a stable meal rhythm, and microbiota[G] support can reduce this inflammation and improve metabolism.
Insulin resistance[G] is not a permanent state. When the environment — sleep, movement, meal rhythm, microbiota[G] — stabilizes, fat-cell size shrinks, and insulin sensitivity[G] can improve.
Diagnostic thresholds for insulin resistance assessment
In clinical practice, the evaluation of insulin resistance[G] and associated metabolic syndrome (MetSyn) is not based on a single lab parameter but requires a matrix-style interpretation. The thresholds below form the basis for discussion with the treating physician — they are not diagnostic on their own, but should be interpreted as part of the full clinical picture. Source: ATP III, IDF, ADA 2024.
| Parameter | Threshold / target | Clinical meaning |
|---|---|---|
| HOMA-IR[G] | >2.5 / >3.5 / >5.0 | Suspected IR / clear IR / severe IR |
| Fasting insulin[G] | >100 pmol/L (>15 mIU/L) | Significant IR indicator |
| HbA1c[G] | 5.7–6.4% / ≥6.5% | Prediabetes / diabetes (ADA 2024) |
| Fasting glucose | 5.6–6.9 mmol/L (100–125 mg/dL) | Prediabetes |
| TG/HDL ratio | >3.0 / >5.0 | IR surrogate / atherogenic dyslipidemia |
| Triglycerides | ≥1.7 mmol/L | MetSyn criterion |
| HDL | men <1.03 / women <1.29 mmol/L | MetSyn criterion |
| Waist circumference | men ≥94 cm, women ≥80 cm | IDF MetSyn criterion (European) |
| Blood pressure | ≥130/85 mmHg | MetSyn criterion |
| HOMA-β | <50% | Reduced β-cell reserve |
| Adiponectin | <4 µg/mL | Low — elevated IR risk |
For a MetSyn diagnosis per IDF, central obesity (waist circumference threshold) plus two additional criteria are required (TG, HDL, blood pressure, fasting glucose). A mildly elevated HOMA-IR[G] alone is generally reversible through lifestyle intervention; severe IR (>5.0) or HbA1c[G] trending toward diabetes may require pharmacological intervention.
Summary of the 3-day goal: to understand that insulin resistance[G] is not a single-cause condition but can be a consequence or a transient adaptation. A lifestyle pattern is established that reduces sustained insulin load.
- Lifestyle Journal updated with meal times and the hunger scale
- 3 main meals per day at stable times
- Avoidance of late-night eating
- At least 6,300 steps/day
- Daily fluid target of at least 1.7 liters (2×200 ml in the morning, at least 900 ml during the day, 2×200 ml in the evening)
Why does insulin resistance[G] develop?
- Adipocyte hypertrophy (pathological enlargement of fat cells): when fat cells grow too large, oxygen deficit develops within them, producing inflammatory signaling molecules and worsening insulin sensitivity[G].
- A lock on the stores: chronically elevated insulin blocks lipolysis[G] (fat breakdown), so fat is not an accessible energy source even with full stores.
- Visceral inflammation: abdominal fat shows increased inflammatory activity and, via the portal circulation, directly worsens the liver’s insulin response (hepatic insulin resistance[G]).
- Microbial endotoxins: in dysbiosis[G], LPS[G] (lipopolysaccharide[G]) released from gut bacteria crosses the leaky gut wall into the circulation (metabolic endotoxemia[G]) and triggers low-grade systemic inflammation, further worsening cellular insulin sensitivity[G].
Pillars of treatment (3-day protocol):
- Metabolic quiet: maintain 3 main meals per day without snacking, so insulin levels have time to return to baseline.
- Protein anchor + fiber shield: provide at least 25–35 g of protein and a fiber source at every meal for a smoother glucose response.
- Postprandial[G] (after-meal) movement: a 10–15 minute walk right after eating — muscle contraction causes glucose-uptake proteins (GLUT4[G]) to reach the cell surface even without insulin[G], supporting glucose uptake by the muscles.
- Microbiota[G] support: fermentable fibers and targeted probiotic[G] strains can reduce LPS[G] load from the gut, easing low-grade systemic inflammation.
“Insulin resistance[G] is not just a defect — it is also a signal. The body adapts to its environment. A stable rhythm reduces resistance.”
You already know the rhythm — meal times, walking, hunger scale — from earlier chapters. Today, pay attention to this: when did you have the most energy, and when did you feel tired or hungry shortly after a meal?
- Record meal times in the Lifestyle Journal
- Hunger scale before every meal (1–5)
- Note late-night meals
- 10-minute walk after meals
- Mental task: when was I tired or hungry shortly after a meal — note 2–3 specific examples; we will come back to them tomorrow
- 3 main meals, no calorie intake in between
- Every meal should contain protein and a fiber source
- Fixed sleep and wake times ±30 minutes
- Step count at least 6,300
- Mental task: look at yesterday’s list — what do the meals that caused fatigue or early hunger have in common? (Was protein missing? Was the storage break too short? Did you eat late?)
- Eating window no more than 12 hours
- 10-minute walk after meals
- Fluid intake: at least 1.7 l
- Break up sitting every hour with brief movement
- Mental task: when was no snacking needed — what was different about that meal? (Protein content, timing, or fiber?)
- body weight;
- meal times and contents (B–D);
- post-meal walk (Y/N);
- daily protein intake (g);
- energy density[G] (0/+/++);
- NOVA[G] level;
- sleep quality (1–5);
- hunger scale (1–5);
- step count;
- bedtime / wake time (AC, AD);
- stool Bristol (1–7);
- bloating;
- daily stool count;
- fluid intake (l);
- UltraBiome dose;
- LOT identifier;
The goal of these 3 days is to improve insulin sensitivity[G], stabilize appetite signaling, strengthen the circadian rhythm[G], and support gut motility[G] and microbiota[G] function.
References
[124] Cani PD, Amar J, Iglesias MA et al. Metabolic endotoxemia initiates obesity and insulin resistance. Diabetes. 2007. Link
Bacterial lipopolysaccharide (LPS) is identified as a triggering factor for insulin resistance, obesity and diabetes. Plasma LPS fluctuates with feeding/fasting and a 4-week high-fat diet chronically increased it 2-3-fold (“metabolic endotoxemia”) while increasing the proportion of LPS-containing gut microbiota. Inducing comparable metabolic endotoxemia in mice via continuous subcutaneous LPS infusion for 4 weeks reproduced the high-fat-diet phenotype: increased fasting glycaemia and insulinaemia, weight gain, adipose F4/80+ inflammation, and hepatic triglyceride accumulation.