Browse the evidence

Preoperative correction of nutritional deficiencies is recommended to mitigate the increased risk of postoperative deficiencies, as surgery further impacts oral intake and absorption.

Before your surgery, get your blood work done. If you are low in iron, Vitamin D, or B12, your dietitian will help you correct it. This gives you the best possible starting point for recovery.

Daytime napping, particularly long-duration naps (>= 1 hour), is associated with an increased risk of all-cause mortality, type 2 diabetes, and chronic respiratory disease, likely serving as a marker for underlying health issues or sleep deprivation compensation.

If you find yourself needing long daytime naps (over 1 hour), view it as a signal to prioritize your nighttime sleep. Long naps are associated with higher risks of diabetes and mortality, especially in older adults. Focus on getting 7-8 hours of quality nighttime sleep rather than relying on long daytime naps to compensate.

Higher dietary intake of vegetables and potassium is associated with a significantly decreased odds of developing incident chronic kidney disease (CKD).

If you do not have diagnosed kidney disease, increasing your intake of vegetables and potassium-rich foods is a proven way to lower your risk of developing kidney disease later in life. Focus on whole food sources like vegetables rather than supplements, as the study highlights dietary patterns. This is a primary prevention strategy, not a treatment for existing kidney damage.

Body fat percentages of 32-35% in women are associated with adverse skeletal outcomes, suggesting a lower obesity cutoff for older women than the WHO standard of 40%.

For older women, aim for a body fat percentage below 32-35% to protect bone health, rather than relying on the standard 40% cutoff.

Testosterone therapy in transgender men is associated with virilization (deepening voice, increased muscle mass, cessation of menses) and is considered safe regarding cardiovascular and oncological disease in the short- to mid-term.

Testosterone therapy for transgender men causes virilization, including voice deepening (which is permanent), increased muscle mass, facial/body hair growth, and cessation of menses. It is considered safe for cardiovascular and cancer risk in the short to mid-term, though long-term data is still being gathered.

Sleep deprivation causes a muted immune response to vaccination, specifically demonstrated by a reduced immune response to flu vaccination.

Ensure adequate sleep when receiving vaccinations, as sleep deprivation may reduce the effectiveness of the immune response.

Bariatric surgery is associated with a significantly lower risk of incident macrovascular disease (composite of coronary and cerebrovascular events) compared to usual medical care in patients with type 2 diabetes and severe obesity.

For patients with severe obesity and type 2 diabetes, bariatric surgery is associated with a significantly lower risk of heart attacks and strokes compared to standard medical care. While lifestyle and medication are important, they may not be sufficient to prevent these major cardiovascular events in this population.

Bariatric surgery is associated with a significantly lower risk of incident coronary artery disease (CAD) compared to usual medical care in patients with type 2 diabetes and severe obesity.

For patients with severe obesity and type 2 diabetes, bariatric surgery is associated with a significantly lower risk of coronary artery disease (heart attacks, angina, interventions) compared to standard medical care.

Exercise-induced irisin promotes the browning of white adipose tissue and increases energy expenditure, offering a potential therapeutic mechanism for managing obesity and metabolic syndrome.

Exercise is beneficial for metabolic health, partly through mechanisms involving irisin and fat browning, but you cannot currently rely on blood tests for irisin to track progress or prescribe specific doses. Focus on consistent physical activity, particularly resistance training, which may influence irisin pathways, rather than seeking 'irisin-boosting' supplements which lack robust human validation.

Irisin acts as an insulin-sensitizing hormone that facilitates glucose uptake in skeletal muscle and improves hepatic glucose metabolism, potentially reducing the risk of type 2 diabetes.

Exercise improves glucose metabolism through multiple pathways, including irisin-mediated effects. Do not expect irisin supplementation to cure diabetes. Focus on resistance and aerobic exercise to naturally support insulin sensitivity and glucose uptake.

Pandemic-related lockdown measures and loss of structure exacerbate eating disorder symptoms, specifically increasing dietary restriction in anorexia nervosa and binge-eating urges in bulimia nervosa and binge-eating disorder.

If you have an eating disorder, the removal of daily structure (meals, therapy, exercise) is a major trigger for symptom worsening. To mitigate this, you must proactively recreate external structures: schedule meals, maintain therapy contact (even via telehealth), and establish a daily routine, as the absence of these is directly linked to increased restriction or bingeing.

Intermittent fasting protocols (specifically Alternate Day Fasting and Time-Restricted Feeding) reduce cardiovascular risk factors by lowering LDL cholesterol, triglycerides, and blood pressure, and by modulating inflammatory biomarkers such as CRP and leptin.

If you have high blood pressure or high LDL, trying an intermittent fasting protocol like 16:8 or 5:2 may help improve your lipid profile and blood pressure. However, results vary; some people see significant drops in LDL and BP, while others see no change. It is not a guaranteed fix for everyone, but it is a viable alternative to continuous calorie restriction, especially if you find daily dieting hard to stick to.

Intermittent fasting improves cardiovascular health by increasing adiponectin levels and reducing pro-inflammatory markers (CRP, IL-6, TNF-alpha) and leptin, which contributes to anti-atherosclerotic effects.

Fasting may help reduce chronic inflammation and improve arterial health by boosting adiponectin, a protective hormone. While weight loss is a major driver, the hormonal changes themselves (lower leptin, higher adiponectin) offer independent cardiovascular benefits.

Probiotic intake improves glucose homeostasis (reducing fasting glucose, HbA1c, insulin, and HOMA-IR) and liver enzymes (ALAT, ASAT) in subjects with Type 2 Diabetes and Non-Alcoholic Fatty Liver Disease (NAFLD), respectively.

If you have Type 2 Diabetes or Fatty Liver Disease, taking multispecies probiotics (containing Lactobacillus or Bifidobacterium strains) daily may help slightly lower your blood sugar, insulin levels, and liver enzymes. However, because these findings are heavily based on studies from Iran, the results may not apply universally. Continue your prescribed medications and consult your doctor before adding probiotics.

Dietary polyphenols prevent and manage Type 2 diabetes mellitus through insulin-dependent mechanisms (protection of pancreatic islet β-cells, reduction of apoptosis, promotion of proliferation, attenuation of oxidative stress, activation of insulin signaling, and stimulation of insulin secretion) and insulin-independent mechanisms (inhibition of glucose absorption, inhibition of digestive enzymes, regulation of intestinal microbiota, modification of inflammation response, and inhibition of advanced glycation end products formation).

Incorporate polyphenol-rich foods (like berries, tea, coffee, and wine) into your diet as part of a broader strategy for managing Type 2 Diabetes. Do not rely on isolated polyphenol supplements as a substitute for prescribed medication, as clinical evidence for their standalone therapeutic effect is currently limited.

Specific polyphenols (resveratrol, curcumin, and anthocyanins) have demonstrated antidiabetic activity in human studies, whereas the therapeutic effect of individual flavonoids or isoflavones in patients is not supported by current clinical data.

If you are looking to use polyphenols for diabetes management, focus on dietary sources rich in resveratrol (grapes/wine), curcumin (turmeric), or anthocyanins (berries), as these have shown activity in human studies. Avoid relying on generic flavonoid supplements which lack therapeutic evidence in patients.

Higher adherence to the Mediterranean Diet (MD) is significantly associated with lower testosterone levels and reduced clinical severity (hirsutism) in women with Polycystic Ovary Syndrome (PCOS).

For women with PCOS, simply counting calories may not be enough to manage hormonal symptoms like high testosterone or hirsutism. Prioritizing a Mediterranean-style diet—rich in fiber, healthy fats (olive oil, nuts, fish), and complex carbohydrates—is associated with significantly lower testosterone levels and reduced clinical severity, independent of total calorie intake.

Lower adherence to the Mediterranean Diet in women with PCOS is associated with adverse body composition, specifically lower Phase Angle (PhA) and Fat-Free Mass (FFM).

Women with PCOS often have worse body composition (lower muscle mass and cellular health, indicated by Phase Angle) than healthy women of the same weight. Improving diet quality through a Mediterranean approach may help preserve Fat-Free Mass and improve cellular health markers, even if weight loss is not the primary goal.

Consumption of fermented foods containing live lactic acid bacteria (LAB) delivers high loads of viable microbes (up to 10^9 CFU/g or ml) to the human gastrointestinal tract, contributing to the transient gut microbiome and offering health-promoting properties via metabolic activity.

Eat fermented foods like yogurt, kefir, kimchi, and sauerkraut that contain live cultures. These deliver billions of bacteria to your gut, which may support health through metabolic byproducts and transient microbial presence. Avoid assuming all fermented foods (like bread or beer) contain live bacteria, as heat or processing often kills them. For maximum benefit, choose artisanal or refrigerated products over heavily processed shelf-stable versions.

Subclinical magnesium deficiency, defined by intracellular depletion despite normal serum levels, is a principal driver of cardiovascular disease and chronic conditions like diabetes and hypertension.

Standard blood tests often miss magnesium deficiency because they only measure a small fraction of your body's total stores. To support heart health and prevent chronic disease, focus on magnesium-rich whole foods (nuts, seeds, dark leafy greens) and consider supplementation if your diet is heavily processed, as modern food crops are increasingly depleted of magnesium. Aim for higher-than-minimum intake to maintain optimal intracellular levels.

Dietary factors such as high phosphorus (from soft drinks and processed foods) and high calcium intake increase magnesium requirements and exacerbate magnesium deficiency.

If you consume a lot of soda, processed meats, or take calcium supplements, you may need more magnesium. Modern diets have shifted the calcium-to-magnesium ratio significantly higher, which can worsen magnesium deficiency. Balance your intake by reducing processed foods high in phosphoric acid and ensuring you get enough magnesium from whole foods.

Excessive fructose intake increases plasma uric acid levels, which acts as a biomarker and potential mediator for insulin resistance and metabolic syndrome.

Be aware that high fructose intake can raise uric acid levels, which is linked to insulin resistance and metabolic syndrome. This risk is higher with sugary beverages and hypercaloric diets.

Western dietary patterns (high fat/sugar) cause gut dysbiosis and 'leaky gut' (increased permeability), allowing bacterial endotoxins (LPS) to enter circulation, triggering systemic and neuro-inflammation.

Eating a Western diet (high fat/sugar, low fiber) damages your gut barrier, letting toxins into your blood and brain, causing inflammation. To protect your brain, prioritize fiber and reduce saturated fats to support a healthy gut barrier and reduce inflammation.

Disruption of circadian rhythms and sleep loss alters gut microbiota composition (dysbiosis), leading to increased intestinal permeability and systemic low-grade inflammation, which contributes to metabolic dysfunction and mood disorders.

Prioritize consistent sleep schedules and duration. If you are a shift worker or experience jet lag, be aware that your gut health and metabolic risk are compromised. Restoring circadian alignment is a prerequisite for optimal gut barrier function and metabolic health.