Browse the evidence

Following a 6-month calorie restriction-induced weight loss, resting metabolic rate (RMR) does not significantly adapt (decrease beyond prediction based on body composition), whereas energy expenditure for physical activity (EEPA) significantly decreases, yet neither component's adaptation predicts subsequent weight regain.

Don't fear that your metabolism has permanently slowed down after losing weight. This study shows that while you might move less (lower EEPA), your resting metabolic rate stays proportional to your new body size. More importantly, these metabolic changes didn't predict who would regain weight, suggesting that behavioral factors, not just metabolic adaptation, are key to maintenance.

Caloric restriction (14% reduction for 2 years) reduces circulating C3a levels in humans, independent of BMI changes, thereby suppressing complement-mediated inflammation.

Adopting a moderate caloric restriction (around 14% less than maintenance) for an extended period (e.g., 2 years) can significantly lower specific inflammatory markers like C3a in the blood. This reduction happens regardless of how much weight you lose, suggesting that the act of eating less directly modulates your immune system to reduce age-related inflammation.

Integrase strand transfer inhibitors (INSTIs), particularly dolutegravir and bictegravir, cause significant weight gain and treatment-emergent obesity in people living with HIV, with effects most pronounced in women and Black individuals.

If you are living with HIV and starting or switching to an INSTI-based regimen (like dolutegravir or bictegravir), be aware that significant weight gain is a known side effect, especially if you are a woman or Black. Monitor your weight closely. If you experience excessive gain, discuss switching to a regimen with a lower weight gain profile (like one using TDF instead of TAF) with your provider.

Genetic variation in the GLP1R locus is associated with cardiometabolic traits (BMI, blood pressure, type 2 diabetes) across diverse ancestries, but these variants do not influence GLP1R gene expression in a way that explains mental ill-health (MIH) endophenotypes.

If you are taking or considering GLP-1 receptor agonists (like semaglutide or tirzepatide) for weight loss or diabetes, be aware that any mental health benefits you experience are likely not due to the drug acting directly on your GLP-1 receptors. Genetic evidence suggests these behavioral effects operate through different mechanisms, possibly involving other genes or secondary metabolic improvements.

Orlistat produces minimal weight loss (2.78-3.16%) and has a high gastrointestinal side effect profile, making it a less effective first-line treatment compared to GLP-1RAs.

Orlistat is an over-the-counter medication that produces minimal weight loss (approx 3%). It has significant gastrointestinal side effects and is considered less effective than prescription options like GLP-1RAs. It is not recommended as a first-line treatment.

Approximately 10% of the U.S. population consumes more than 5000 mg of sodium per day, which is more than twice the recommended limit of 2300 mg/day, with extreme intake levels showing no meaningful decline between 2003 and 2018.

Check your sodium intake if you are in the top 10% of consumers. If you are eating more than 5000mg daily, you are consuming more than double the recommended limit. This level of intake is associated with higher cardiovascular risk and is not declining in the population, suggesting a need for targeted reduction strategies.

Sodium intake among boys in the U.S. shows an alarming accelerating increase over time, whereas girls show a steady decline, indicating a diverging gender trend in extreme sodium consumption.

Parents of boys should be particularly vigilant about sodium intake, as trends show it is accelerating in this group. Focus on reducing processed foods and restaurant meals, which are the main sources of sodium.

Current sodium reduction efforts in the U.S. are insufficient to meet the WHO's global target of a 30% sodium reduction by 2030, as extreme intake levels remain high and show no meaningful decline.

Current public health strategies are not working to reduce extreme sodium intake. More aggressive interventions are needed to meet global health targets.

Elevated plasma levels of GDF15 and its receptors (RET and GFRAL) mediate the causal relationship between smoking intensity and reduced adiposity (lower BMI and body fat percentage).

Smoking suppresses weight partly through the GDF15 protein pathway. When people quit, this pathway downregulates, potentially leading to weight gain. Future treatments might target GDF15 (e.g., using drugs like metformin to boost it) to help people quit without gaining weight, rather than relying solely on nicotine replacement.

Genetically proxied exposure to GLP-1 receptor agonists is associated with a significantly reduced risk of Obstructive Sleep Apnea (OSA).

If you have OSA and obesity, GLP-1 agonists (like semaglutide or liraglutide) may help reduce your OSA risk by addressing underlying metabolic factors. This is supported by genetic evidence, but clinical trials are still needed to confirm efficacy in diverse populations. Consult your doctor to see if this is a suitable adjunct to your current OSA treatment.

Weekly injectable semaglutide demonstrates very low persistence in real-world Colombian patients, with a mean duration of use of only 93.7 days and less than 1% persistence at 12 months.

If you are starting weekly injectable semaglutide, be aware that persistence is very low in real-world settings. Most people stop within 3 months. To stay on the medication, ensure you have good access, receive proper education on how to inject, and have regular follow-up with your doctor to manage tolerability.

Leptin acts as a critical signal linking nutritional status to puberty onset and reproductive function in females, with sufficient levels required to activate hypothalamic pathways for ovulation.

For females, maintaining healthy body fat levels is crucial for the onset of puberty and regular ovulation. Leptin, a hormone from fat cells, signals the brain that energy reserves are sufficient for reproduction. Extreme leanness can delay puberty or cause infertility, which may be reversible with leptin treatment.

Access to effective obesity pharmacotherapy is severely limited by cost, insurance prior authorization, and systemic inequities, leading to high discontinuation rates.

Even if your doctor prescribes a weight loss drug, insurance may not cover it, or it may be too expensive. You might face delays due to prior authorizations. Ask your doctor about manufacturer assistance programs or alternative coverage options.

Initiation of GLP-1 receptor agonists is associated with a small but statistically significant increased risk of acute pancreatitis, particularly during the first 6 months of treatment.

Be aware that GLP-1 RAs carry a small increased risk of acute pancreatitis, especially in the first 6 months. If you have a history of pancreatitis, discuss this carefully with your doctor. Report severe, persistent abdominal pain to your provider immediately, as it could be a sign of pancreatitis.

SGLT2 inhibitors lower blood pressure primarily through early osmotic diuresis and volume contraction, with sustained effects driven by reduced arterial stiffness and improved endothelial function.

If you have heart failure or diabetes, SGLT2 inhibitors (like Jardiance or Farxiga) will likely lower your blood pressure slightly, but this is a bonus, not the main reason for taking them. The benefit comes from reducing fluid volume and improving artery health, not just sugar control.

Existing patient-reported outcome (PRO) measures inadequately capture the full spectrum of emotional impacts of obesity and weight loss, specifically missing concepts such as feeling happy, energetic, proud, or joyful, as well as negative emotions like grief, disappointment, or skepticism.

If you are tracking the success of your weight loss journey, standard health surveys might not reflect how you truly feel. This research suggests that specific emotional changes—like feeling more energetic, confident, or joyful—are real and significant benefits of treatment, but they are often missed by standard medical questionnaires. To get a complete picture of your progress, use or advocate for tools specifically designed to measure emotional well-being in the context of weight, such as the Weight and Emotions Scale (WES).

GLP-1 receptor agonist treatment alone, despite causing significant weight loss, does not improve physical functional performance or cardiorespiratory fitness compared to placebo.

Taking GLP-1 medication will help you lose weight, but it will not make you more physically fit or improve your ability to perform daily tasks. If you rely solely on medication, you may lose weight but not gain the stamina or functional strength that exercise provides. To improve fitness, you must add structured exercise.

GLP-1 and dual GLP-1/GIP receptor agonists cause predictable, dose-dependent gastrointestinal adverse events (nausea, vomiting, diarrhea, constipation) that are generally mild to moderate and transient, though they significantly impact treatment adherence.

Expect digestive side effects like nausea or constipation when starting GLP-1 medications. These are common, usually mild, and tend to improve as your body adjusts. To minimize them, start with the lowest dose and increase slowly as directed by your doctor. Staying hydrated and eating smaller meals can help manage symptoms.

Epigenetic silencing of the GLP-1 receptor (GLP-1R) via DNMT3A-mediated hypermethylation impairs incretin signaling and insulin secretion in pancreatic beta-cells.

In Type 2 Diabetes, the body's ability to respond to GLP-1 (a hormone that stimulates insulin) is often turned off by epigenetic silencing of the GLP-1 receptor. This silencing is driven by enzymes like DNMT3A. Understanding this mechanism highlights why therapies that target these epigenetic modifiers or mimic GLP-1 (like GLP-1 agonists) are effective, as they bypass or reverse this specific block in insulin secretion.

Classical anti-obesity agents (orlistat, phentermine-topiramate, naltrexone-bupropion) typically achieve only modest weight loss (3-10%) and are limited by tolerability and safety concerns.

Orlistat is an older, oral weight loss medication that helps block fat absorption. It typically leads to modest weight loss (3-5%) and can cause gastrointestinal side effects like oily stools. It is generally reserved for patients who cannot access or tolerate newer, more effective injectable therapies.

Multi-agonist therapies (GLP-1/GIP, GLP-1/Glucagon, GLP-1/GIP/Glucagon) do not inherently offer better tolerability than GLP-1 monotherapy; in fact, glucagon receptor activation may increase nausea and vomiting rates.

Do not assume that newer, multi-agonist weight loss drugs are easier on your stomach than older GLP-1 drugs. Some of these newer drugs actually cause more nausea because they target additional receptors that can trigger vomiting. You still need to start with a low dose and go slow, regardless of how many receptors the drug targets.

GLP-1 receptor agonist therapy induces predictable reductions in fat-free mass (approximately 30-40% of total weight loss) due to sustained negative energy balance, not direct catabolic effects.

Expect that about a third of your weight loss on GLP-1s will be muscle/fluid, not just fat. This is normal physiology, not a side effect. To mitigate this, prioritize protein intake and resistance training, especially if you have low testosterone.

Continuous positive airway pressure (CPAP) alone does not significantly reduce cardiovascular disease (CVD) outcomes in patients with obstructive sleep apnea (OSA).

If you have sleep apnea, using CPAP is important for your breathing and sleep quality, but it is not enough to protect your heart on its own. You must actively manage other risk factors like weight, blood pressure, and cholesterol through lifestyle changes and medical management.

Combination therapy with ARNIs and SGLT2 inhibitors produces synergistic cardiovascular, metabolic, and renal benefits in cardiometabolic syndrome (CMS) patients, though implementation is hindered by hypotension risks and cost.

If you have cardiometabolic syndrome, current guidelines suggest combining an ARNI (like sacubitril/valsartan) with an SGLT2 inhibitor (like empagliflozin or dapagliflozin) for the best heart, kidney, and metabolic protection. Start with low doses and increase slowly to avoid dizziness or low blood pressure. Monitor your kidney function and electrolytes regularly. Discuss insurance coverage with your provider, as these drugs can be expensive but are cost-effective long-term by preventing hospitalizations.