Metabolism and reasons for weight gain

Over the last fortnight I have had quite a few women come in to discuss weight loss, a common theme around this time of year as we awaken to more warmth and light it does give us a renewed focus on how we feel in our bodies.

THE REFRAME defining a healthy body composition for you & why it matters. It’s a bit of a mental-emotional trap when the focus is just on weight loss – I see for many women midlife escalates the challenge read on for the key factors I see and work with below. The best approach is always a whole health plan and starting with The Foundation & your personal blueprint with me is an awesome way to work with me.

In this blog edition:

— Metabolism and reasons for weight gain

— Metabolic flexibility

— The timing of food

— Distinguishing phenotypes

Metabolism and reasons for weight gain

— Gut dysbiosis

— Chronic inflammation

— Thyroid and hormone issues

— Nervous system dysregulation

— Insulin resistance, fatty liver

— Medications (Oral Contraceptive Pill, antidepressants etc.)

— Loss of muscle

— Lack of exercise, injury, sedentary lifestyle

— Mitochondrial dysfunction/loss

— Genetic predisposition

— Excess of calories vs expenditure

Metabolism

Thermic effect of food 10% • Basal metabolic rate 70% • Exercise and movement 20% (most variable) • Set point theory

The core drivers

Weight loss resistance is rarely a single-factor problem. In most complex cases, multiple overlapping physiological mechanisms conspire to defend adipose tissue and suppress energy expenditure. Identifying which drivers are dominant in each client is an important first step toward a targeted protocol.

Insulin Resistance: Elevated insulin locks fat in adipocytes and impairs metabolic flexibility

Chronic Inflammation: Pro-inflammatory cytokines disrupt leptin signalling and promote fat storage

Cortisol Dysregulation: HPA axis activation drives visceral adiposity and increases appetite

Gut Dysfunction Dysbiosis: and intestinal permeability impair GLP-1 secretion and energy harvest

Disrupted Appetite Signalling: Leptin resistance and ghrelin dysregulation override caloric deficit attempts

Metabolic flexibility: The underdiagnosed deficit — the capacity to switch efficiently between glucose and fatty acid oxidation is a critical determinant of fat loss success. Insulin-resistant, inflexible metabolisers are trapped in a glucose-dependent state, making fat mobilisation physiologically difficult regardless of caloric intent. Mitochondrial adaptation and metabolic inflexibility in obesity further impair this switching capacity.

Signs of poor metabolic flexibility

— Energy crashes between meals or on waking

— Strong carbohydrate cravings, especially in the afternoon

— Inability to fast comfortably beyond 12 hours

— Fatigue with moderate-intensity exercise

Restoring flexibility: Clinical levers

— Protein-forward, lower glycaemic dietary architecture

— Time restricted eating to improve mitochondrial efficiency

— Resistance training to upregulate glucose into cells

— Aerobic training to enhance mitochondrial lipid metabolism

— Magnesium & b-vitamin repletion to support oxidative metabolism

Cortisol patterns: The visceral fat driver - Chronic cortisol elevation is one of the most overlooked drivers of visceral adiposity and weight loss resistance. It operates across multiple pathways simultaneously, causing increased appetite, poor sleep, promoting muscle catabolism and stimulating visceral fat deposition

Clinical signs of cortisol dysregulation

— Central weight gain despite caloric deficit, Elevated fasting glucose

— Afternoon energy crashes and carbohydrate cravings at 3–4 pm

— Poor sleep onset or early waking (cortisol awakening response disruption)

— High perceived stress, anxiety, and low mood

Clinical interventions

— Circadian alignment and sleep support using magnesium, herbal medicine such as Withania, Saffron, Passionflower, etc.

— Protein focus, meal timing, personal phenotype (biology - hormonal, metabolic, or psychological driver) support and appropriate exercise and rest/HPA axis (stress response) support

— Address lifestyle stressors

Circadian rhythm and chrono nutrition

The timing of food intake relative to circadian biology has meaningful effects on insulin sensitivity, fat oxidation, and appetite regulation — independent of total caloric intake. Circadian misalignment (irregular meal timing, late-night eating, shift work) is a clinically relevant but underappreciated driver of weight loss resistance.

Front-load calories

Insulin sensitivity is highest in the morning. A larger breakfast and smaller evening meal improves glycaemic control and supports fat oxidation overnight.

Eating window

A 10–12 hour eating window aligned to daylight hours supports circadian entrainment of metabolic hormones, liver function, and gut motility.

Avoid late-night eating

Eating within 2–3 hours of sleep suppresses melatonin, disrupts growth hormone release, and shifts lipid metabolism towards storage rather than oxidation.

Identifying the metabolic phenotype

Not all clients with elevated body fat present the same metabolic picture. Distinguishing phenotypes allows for precision protocol design rather than a one-size-fits-all approach — each requires a distinct therapeutic emphasis.

Putting it all together: the clinical framework

Metabolic phenotype, body composition (Dexa scan or BIA/smart scales), hormones, stress, sleep, gut, inflammation etc

Nourish Protein forward diet, circadian timing, monitor glycaemic load of diet, cyclical calorie deficit which is not always the first approach for midlife.

x Karen