Browse the evidence

The holiday season does not cause significant weight gain in children or college students, though it may increase body fat in college students.

For children and college students, holiday weight gain is not a significant concern based on current data, though college students may see an increase in body fat.

GLP-1 receptor agonists (GLP-1 RAs) improve skeletal muscle mitochondrial morphology, area, and number in animal models of obesity and type 2 diabetes, but their effect on mitochondrial respiration and mass is inconsistent or neutral.

Current evidence for GLP-1 RAs improving muscle mitochondria comes exclusively from animal and cell studies, not humans. While these studies show improved mitochondrial structure, they do not guarantee preserved muscle mass in people. To protect muscle while using GLP-1s for weight loss, prioritize resistance training and adequate protein intake, as the drug's direct benefit to human muscle mitochondria is not yet proven.

Adherence to a vegan diet does not significantly alter the risk of primary cardiovascular disease events (including coronary heart disease, myocardial infarction, or stroke) compared to non-vegan diets, although it may lower intermediate markers like carotid artery intima-media thickness.

Switching to a vegan diet is unlikely to significantly change your risk of having a heart attack or stroke compared to a non-vegan diet, based on current evidence. While vegans may have better intermediate markers like artery thickness, the hard outcomes (heart attacks, strokes) are similar. To maximize heart health on a vegan diet, ensure you are getting adequate B12, Omega-3s (EPA/DHA), and other nutrients, as deficiencies may offset potential benefits.

Vegan diets may be associated with a higher risk of ischemic stroke compared to non-vegan diets, although the finding was not statistically significant.

One study suggested a potential trend toward higher ischemic stroke risk in vegans, but it was not statistically significant. Ensure you are supplementing with B12 and Omega-3s (EPA/DHA) to mitigate any potential risks associated with nutrient deficiencies.

Increases in serum myostatin concentrations following resistance training are positively associated with gains in appendicular skeletal muscle mass in older adults, challenging the view that myostatin solely inhibits muscle growth.

Do not try to manipulate your myostatin levels. This study suggests that myostatin may actually increase as part of the muscle-building process in older adults. Focus on your training and nutrition; do not worry about serum myostatin levels as a barrier to growth.

Targeting hypothalamic AMPK in SF1 neurons using small extracellular vesicles (sEVs) loaded with dominant-negative AMPKα1 plasmids reduces body mass and adiposity by increasing sympathetic nervous system-mediated brown adipose tissue thermogenesis, without affecting food intake.

This technology is currently in preclinical stages (mouse models). While it shows promise for treating obesity by boosting energy expenditure rather than suppressing appetite, it is not yet available for human use. Current clinical options remain focused on lifestyle changes, bariatric surgery, and pharmacological agents like GLP-1 agonists.

Increasing protein intake beyond ~1.8 g/kg/d does not provide additional muscle mass benefits in bodybuilders if total energy intake is already high.

Don't obsess over hitting extremely high protein numbers (like 2.0+ g/kg) if you are already eating enough (around 1.8 g/kg). Focus on your total calories and training intensity instead, as extra protein won't help if your energy balance isn't optimized.

There is no single ideal macronutrient distribution or specific 'diabetes diet'; individualized eating patterns (Mediterranean, low-carb, low-fat, etc.) are all acceptable if they meet metabolic goals and personal preferences.

Don't look for a single 'perfect' diabetes diet. You can choose from various eating patterns (Mediterranean, low-carb, low-fat, vegetarian) as long as they help you meet your blood sugar, lipid, and blood pressure goals. Focus on nutrient-dense foods and personal preferences to find a sustainable plan.

Preclinical evidence suggests GLP-1 receptor agonists may offer cardioprotective benefits beyond weight loss, such as reducing fibrosis and inflammation, but this remains unproven in humans.

Current human trials show GLP-1 benefits are mostly due to weight loss. However, animal studies suggest the drug might also directly reduce heart inflammation and fibrosis. This potential direct benefit is not yet proven in humans, so patients should focus on the proven weight loss benefits while researchers investigate these additional mechanisms.

Combining extended dosing intervals (e.g., every two weeks) with increased dose sizes (e.g., doubling the mg strength) can maintain nearly 100% of the weight loss efficacy while halving the cost.

If you are on a lower dose of a GLP-1 drug (like 5mg tirzepatide) and find the weekly cost prohibitive, ask your doctor about switching to a higher dose (like 10mg or 15mg) taken every two weeks. This strategy can keep your weight loss results nearly identical to taking the lower dose weekly, but at half the cost. This is only possible if your body can handle the higher individual dose without excessive side effects.

At a population level, distributing GLP-1 medications using extended dosing intervals (q2wk) allows twice as many obese adults to be treated for the same total cost, leading to greater reductions in national obesity rates and mortality.

For policymakers and insurers, extending GLP-1 dosing intervals to every two weeks allows the same budget to treat twice as many people. While each individual might lose slightly less weight, the overall public health benefit (reduced obesity and mortality) is significantly higher. This is a key strategy for making these drugs accessible at a national scale.

Percutaneous CT-guided cryovagotomy reduces hunger and caloric intake, leading to statistically significant weight loss and BMI reduction in patients with Class I or II obesity over 6 months.

This procedure targets the vagus nerve to reduce hunger signals. In a small pilot study, it led to an average weight loss of about 5 kg over 6 months in obese patients, largely by reducing their daily calorie intake by about 610 calories. It is not a magic bullet but a tool to help manage appetite.

Treatment with the dual GLP-1/GIP receptor agonist tirzepatide results in a proportional loss of skeletal muscle mass relative to total body weight, with muscle loss constituting approximately 34% of total weight loss in treated patients.

If you are taking tirzepatide, expect to lose some muscle along with fat. This case showed that about one-third of the weight lost was muscle. To counter this, you should prioritize strength training and ensure adequate protein intake, as suggested by the authors, rather than just focusing on the scale number.

Preclinical studies show conflicting results regarding GLP-1 agonists and breast cancer progression: some show inhibition of tumor growth via apoptosis, while others show promotion of growth in aggressive Triple-Negative Breast Cancer (TNBC) cell lines.

Animal studies show mixed results: GLP-1s might slow down some breast cancers but potentially speed up aggressive types (TNBC) in a lab setting. However, large human studies have not found an increased risk of developing breast cancer in people taking these drugs. If you have a history of breast cancer, discuss your specific subtype with your doctor.

Among patients taking oral semaglutide, older adults (65+) achieve significantly better weight loss outcomes than younger adults (<65).

If you are under 65 and taking the oral version of semaglutide, you might not lose as much weight as older patients on the same medication. If weight loss is your primary goal, the injection form is likely a better choice for you, as it provided superior results across all age groups in this study.

Tirzepatide treatment leads to significant weight loss in patients with hypothalamic obesity (HO) resulting from craniopharyngioma resection, despite the condition's historical resistance to standard therapies.

For patients with hypothalamic obesity due to brain tumors or surgery, standard diet and exercise often fail. Tirzepatide, a weekly injection starting at 2.5mg and increasing to 10mg, has shown significant weight loss in case reports. However, adherence is critical, as stopping the medication leads to rapid weight regain. Consult an endocrinologist to discuss if this treatment is appropriate for your specific condition.

Tirzepatide use is associated with novel safety signals including belching, upper respiratory tract infections, and postmenopausal hemorrhage, which are not prominently featured in standard prescribing information.

Be aware that Tirzepatide may be linked to new symptoms not always listed in official documents, such as excessive belching, respiratory infections, or unusual bleeding (especially in postmenopausal women). Report these to your healthcare provider, as they are emerging safety signals.

GLP-1 receptor agonist use may improve specific inflammatory or scarring alopecias (e.g., Folliculitis Decalvans, Central Centrifugal Cicatricial Alopecia) through metabolic modulation and anti-inflammatory effects.

If you have a specific type of hair loss like Folliculitis Decalvans or Central Centrifugal Cicatricial Alopecia, and you are prescribed a GLP-1 agonist for weight or diabetes, it might actually help your hair regrow by improving blood flow and reducing inflammation. This is not guaranteed for everyone, but it is a documented possibility in case studies.

A 16-week nutritional intervention combining whey protein with leucine and fish oil with vitamin D3 increases total lean mass in very old adults with low functional capacity, despite failing to improve physical performance metrics like strength or gait speed.

For very old adults with low function, a specific combination of whey protein (with leucine) and fish oil (with Vitamin D) can increase lean mass by about 0.5 kg over 4 months. However, this did not improve strength or walking speed. Adherence to the fish oil component dropped significantly over time, suggesting that simpler regimens or better palatability might be needed for long-term use.

Tirzepatide exacerbates orthostatic intolerance and causes marked tachycardia in patients with Postural Orthostatic Tachycardia Syndrome (POTS).

If you have POTS and are considering tirzepatide, discuss your specific heart rate response risks with your doctor. This case suggests that standard dosing might cause severe tachycardia in POTS patients, so a lower starting dose (e.g., 2.5 mg) and close monitoring of heart rate and orthostatic symptoms are critical to prevent exacerbation.

Tirzepatide use is associated with a potential risk of acute deep vein thrombosis (DVT), particularly in patients with predisposing risk factors such as obesity, rapid weight loss, or dehydration.

If you are taking tirzepatide, be aware of signs of blood clots like swelling, pain, or redness in your arms or legs. While rare, this risk exists, especially if you are losing weight rapidly or are obese. Report these symptoms to your doctor immediately.

Tirzepatide may trigger new-onset atrial fibrillation in susceptible individuals through autonomic activation and sinoatrial node effects, despite its overall cardiometabolic benefits.

If you start tirzepatide and feel palpitations, lightheadedness, or a racing heart, seek medical attention promptly. While the drug improves long-term metabolic health, it can increase heart rate and potentially trigger atrial fibrillation in susceptible individuals. Do not ignore new cardiac symptoms.

Coadministration of tirzepatide and SGLT2 inhibitors in Type 1 Diabetes Mellitus patients significantly increases the risk of severe euglycemic diabetic ketoacidosis (euDKA), potentially requiring mechanical ventilation.

If you have Type 1 Diabetes, do not take Tirzepatide or SGLT2 inhibitors together without extreme caution and specialist oversight. Monitor ketones daily, especially if you feel nauseous or vomit, as blood sugar may remain normal while dangerous acidosis builds up.

Timing of protein ingestion (before vs. after resistance training) does not significantly affect total body lean mass gains.

You do not need to rush to drink protein immediately after your workout. As long as you consume your protein within a few hours before or after training, your muscle growth will be the same. Focus on getting enough total protein throughout the day rather than stressing about the exact timing.