Answered questions
Metabolism
120 answered questions · 808 studies
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What is spermidine and where is it found?
Spermidine is a molecule that occurs naturally in your body, declines with age, and that you also obtain through fermented…
Yes · Moderate evidence
What does taurine do in your body?
Taurine has several demonstrable functions in your body: it supports the retina, heart, and brain, and helps cells maintain…
Yes · Moderate evidence
Does berberine help with weight loss?
Berberine leads to modest weight loss in some studies, but a large well-designed study found no effect on visceral fat. It is…
Moderate evidence
Can early liver fat accumulation and fibrosis be reversed by addressing the underlying metabolic causes?
Early liver fat accumulation and even fibrosis are largely reversible through weight loss of 10% or more. Start with a…
Yes · Moderate evidence
What are the effects of microdosing with Ozempic?
Microdosing with Ozempic has not been studied, so nobody knows whether it works or is safe. If you are considering using…
Insufficient evidence
What do mitochondrial mutations mean for how quickly you age?
Mitochondrial mutations and dysfunction likely contribute to faster biological ageing. You cannot control the accumulation of…
Yes · Moderate evidence
Does a fasting-mimicking diet work better than simply eating less?
There is currently no convincing evidence that a fasting-mimicking diet works better than simply eating less. For weight loss…
Preliminary evidence
What does urolithin A do to your muscles and mitochondria?
Urolithin A shows positive effects on mitochondrial health and muscle strength in small studies, but the evidence is still…
Yes · Moderate evidence
Does a NAD+ infusion do something that an NMN pill does not?
There is no study that directly compares a NAD+ infusion with an oral NMN pill, so any advantage of the infusion has not been…
Preliminary evidence
How much berberine do you need per day?
For blood sugar control in type 2 diabetes, berberine works best at a daily dose of 500 to 2000 mg, spread throughout the day;…
Yes · Moderate evidence
What do we really know about metformin and ageing?
Metformin may extend your healthy years by helping to prevent disease, from diabetes to heart and vascular disease. Whether it…
Preliminary evidence
What does stable blood sugar do for healthy ageing?
A stable, low blood sugar is associated worldwide with more healthy life years. The association is clear, but the exact gain…
Yes · Moderate evidence
Do your hormones influence how quickly you age?
Hormones do influence ageing, but do not control it entirely. Fat distribution, muscle mass and inflammatory processes are all…
Yes · Moderate evidence
Does black seed oil work as a supplement?
Black seed oil has shown measurable effects on blood lipids, blood pressure and inflammatory markers in randomised research,…
Yes · Moderate evidence
Does a NAD infusion (IV drip) make sense?
A NAD infusion has no proven advantage over cheaper oral supplements, and even those show hardly any demonstrable effect in…
No · Preliminary evidence
Does the fasting-mimicking diet such as Prolon actually work?
For healthy people with risk factors such as elevated blood pressure or blood lipids, there are indications that the diet…
Moderate evidence
What works better to raise NAD+: NMN or NR?
Based on the only direct head-to-head comparison study in humans, NMN and NR perform equally well for raising NAD+, so for now…
Moderate evidence
Which form of iron is best absorbed?
Haem iron from meat, fish and poultry is clearly better absorbed than the form of iron from plant-based foods. If you eat…
Strong evidence
What is the relationship between fatty liver and type 2 diabetes?
Fatty liver and type 2 diabetes mutually reinforce each other: they share the same underlying mechanism and roughly double…
Does excess weight really make your hormones worse?
Excess weight disrupts your hormones in multiple ways simultaneously, and this is not a coincidental association. In men,…
Does chewing slowly really help with better digestion?
Chewing well certainly helps form a smooth food bolus and increases saliva production, but whether it actually leads to better…
Preliminary evidence
How does your body fat affect hormone production as you get older?
Body fat has a considerable influence on your hormonal balance as you age: more abdominal fat disrupts insulin sensitivity,…
What does caffeine do to your stress hormones when you drink a lot of it?
High caffeine intake raises your cortisol, especially during stress or exercise and later in the day; you partially adapt to…
Does the order in which you eat your food affect your digestion?
Yes, the order in which you eat affects your blood sugar and digestion speed: eating protein or vegetables first and…
Yes · Moderate evidence
What is the role of bile acids in healthy digestion?
Bile acids are indispensable for proper fat digestion and the absorption of fat-soluble vitamins. If you suffer from greasy…
Can low blood sugar disrupt your hormones, and how do you notice it?
Low blood sugar immediately raises stress hormones and causes symptoms such as trembling, sweating and irritability. People…
Yes · Moderate evidence
Are the gut bacteria of lean people different from those of heavier people?
The gut bacteria of people with excess weight differ measurably from those of lean people, but whether those bacteria are the…
What does a high-fat diet do to your gut microbiome?
A high-fat diet noticeably disrupts the gut microbiome: less bacterial diversity, more harmful species and a leaky gut wall…
Does having type 2 diabetes increase your risk of certain cancers?
Type 2 diabetes increases the risk of several cancers, including liver, pancreatic, uterine and colorectal cancer. If you have…
Does drinking apple cider vinegar help your digestion?
There is no research whatsoever showing that apple cider vinegar improves digestion. If you want to use apple cider vinegar…
No · Preliminary evidence
What happens to your cells when you don't move enough?
Moving too little demonstrably disrupts how your cells handle sugar, signals and inflammatory processes. Even a small increase…
Can your gut microbiome control your appetite and hunger?
Yes, your gut microbiome can influence your hunger and eating behaviour via a direct connection to your brain. Eating more…
Does diabetes increase the risk of bone fractures?
Both type 1 and type 2 diabetes clearly and demonstrably increase the risk of bone fractures. If you have diabetes, discuss…
What does eating too much sugar do to your gut health?
Eating a lot of sugar probably disrupts your gut microbiome and makes the gut wall more permeable, but it is the combination…
What is sleep debt and can you actually pay it back?
Paying off sleep debt over a weekend does not work: after two recovery nights, cognitive functions are still impaired.…
Yes · Moderate evidence
Does someone with diabetes age faster biologically?
Yes, diabetes noticeably accelerates biological ageing: the risk of cardiovascular disease, dementia, and premature death…
Does the timing of meals throughout the day affect your weight?
When you eat matters: meals earlier in the day appear more favourable for your metabolism than eating late, although the…
Yes · Moderate evidence
What does pregnancy do to your hormone balance in the long term?
Pregnancy brings about hormonal changes that are partly temporary, but in the case of gestational diabetes the risk of type 2…
Does eating more fibre help against high blood sugar?
Eating more water-soluble fibre probably helps in lowering high blood sugar, but the overall meal composition also plays a…
Yes · Moderate evidence
What does alcohol do to your blood sugar and insulin sensitivity?
The effect of alcohol on your blood sugar depends strongly on context: on an empty stomach the risk of low blood sugar is…
Does cinnamon really lower your blood sugar?
Cinnamon can modestly lower fasting blood sugar in type 2 diabetes, but whether that makes any meaningful difference to…
Moderate evidence
Does fasting (intermittent fasting) help improve your insulin levels and other hormones?
Fasting probably improves your insulin levels, but most studies are small and short-term. Eating early in the day appears to…
Yes · Moderate evidence
Does it matter for your weight whether your calories come from fat or carbohydrates?
In the long term, the ratio of fat versus carbohydrates matters little for your weight, as long as your total calorie intake…
No · Strong evidence
Does strength training work better against high blood sugar than cardio?
Strength training appears to work better than cardio alone in people with diabetes and a normal weight, but in overweight…
Moderate evidence
Does being overweight affect your bone density?
Being overweight does not straightforwardly increase bone density, and the location and amount of fat strongly determine…
What does chronic stress do to your weight in the long run?
Chronic stress contributes to long-term weight gain and abdominal fat through elevated cortisol, inflammation, and less…
How bad is sitting for too long for your blood sugar and metabolism?
Sitting for long uninterrupted periods noticeably impairs your blood sugar and metabolism, but short breaks of 2-3 minutes of…
What is glycation and how does sugar damage your cells from the inside?
Sugar damages your cells through a chain of chemical reactions that affect proteins, power plants, and small blood vessels.…
Does type 2 diabetes increase your risk of dementia?
Type 2 diabetes substantially increases the risk of dementia, and the younger you are at diagnosis, the greater that risk.…
What is the difference between high blood sugar and a blood sugar spike?
Chronically high blood sugar and a blood sugar spike are two different things that each require their own approach. If your…
What does alcohol do to your hormones when you drink it regularly?
Drinking alcohol regularly disrupts your hormonal balance in several ways: testosterone falls in men, cortisol rises…
Does cold showering or an ice bath speed up your metabolism?
Cold water clearly speeds up metabolism for as long as you are in it, but whether this produces any meaningful effect on…
Moderate evidence
What does excess weight do to your inflammation levels?
Excess weight structurally raises your inflammation levels through multiple biological pathways. Exercise, and strength…
What does intermittent fasting do to your insulin sensitivity?
Intermittent fasting improves insulin sensitivity in most people, but be aware of possible muscle loss and hormonal effects,…
Can too much sugar weaken your immune system?
Chronically high blood sugar levels, as seen in diabetes or severe obesity, demonstrably weaken immune defences. For healthy…
Moderate evidence
Can poor sleep cause me to develop diabetes sooner?
Consistently sleeping too little or poorly demonstrably increases your risk of type 2 diabetes, so it is worthwhile taking…
Yes · Moderate evidence
What does excess weight do to your brain in the long run?
Excess weight harms your brain in multiple ways at once: less brain tissue, weaker connections and a higher risk of dementia.…
Does muscle tissue burn more calories than fat, even at rest?
Muscle tissue burns more calories at rest than fat tissue, and strength training produces a measurable increase in resting…
What is visceral fat and why is it more dangerous than subcutaneous fat?
Visceral fat is more dangerous than subcutaneous fat because it acts directly on the liver, releases more inflammatory…
Does the order in which you eat food and vegetables during a meal matter?
Eating vegetables and/or protein first and carbohydrates last demonstrably blunts the post-meal blood sugar spike, even in…
Yes · Moderate evidence
Does magnesium help with insulin resistance?
There is a reasonable amount of evidence that magnesium has a beneficial effect on insulin resistance, particularly if your…
Yes · Moderate evidence
Why do you gain weight more easily after 40, even if you eat the same amount?
After forty, your body burns fewer calories, mainly due to muscle loss and a lower resting metabolism. You therefore do not…
Does a large belly increase my risk of cancer more than being simply overweight?
A large belly raises the risk of colorectal cancer in particular more than ordinary overweight does, and measuring your waist…
Yes · Moderate evidence
Is brown fat really different from regular fat, and can I activate it?
Brown fat is genuinely different from regular fat and you can activate it, with cold exposure having the strongest evidence.…
Yes · Strong evidence
What does chronically high cortisol do to your belly fat and blood sugar?
Chronically high cortisol directs fat toward the abdominal cavity and increases the risk of insulin resistance and type 2…
Does metformin help with weight loss?
Metformin helps with weight loss, but the effect is modest: expect a few kilograms, not a dramatic transformation. Lifestyle…
Yes · Moderate evidence
Can you take metformin without having diabetes?
Metformin has a reasonable evidence base for specific groups without diabetes (prediabetes, PCOS, overweight with insulin…
Moderate evidence
Does strength training help against insulin resistance?
Strength training probably helps against insulin resistance, although the effect is most strongly demonstrated in combination…
Yes · Strong evidence
How do you measure insulin resistance?
There is no single best method for everyone: the clamp is the most accurate but is only feasible in a specialised setting. For…
Does insulin resistance accelerate ageing?
Insulin resistance is associated with measurably faster biological ageing, greater muscle loss, and possibly a higher risk of…
Yes · Moderate evidence
What foods improve your insulin sensitivity?
Diet can clearly improve your insulin sensitivity: a wholesome diet high in fibre, eating your largest meal early in the day,…
Moderate evidence
What are the earliest signs of insulin resistance?
Early signs of insulin resistance are measurable long before a diabetes diagnosis: elevated fasting insulin, abdominal fat,…
Can your HbA1c also be too low?
An HbA1c below 5.0% is associated with an increased risk of death in people without diabetes, although this is likely a signal…
Yes · Moderate evidence
How often should you have your HbA1c measured?
In stable diabetes, measuring twice a year is standard; when values fluctuate or treatment has changed, four times a year is…
Moderate evidence
What does your HbA1c tell you about your risk of diabetes and ageing?
An elevated HbA1c, even well below the official diabetes threshold, is associated with a greater risk of diabetes, kidney…
How do you lower a high HbA1c?
Several medications demonstrably lower HbA1c: the weekly semaglutide injection has the strongest evidence base, but oral…
Strong evidence
What is a healthy HbA1c value?
There is no fixed 'healthy' HbA1c value: lower within the normal range appears to be better, but how low is optimal also…
Do proteins inhibit your autophagy?
Proteins inhibit autophagy because the amino acids in your meal keep mTOR active, the best-known brake on autophagy. If you…
Yes · Moderate evidence
How many hours of fasting are needed to activate autophagy?
There is no proven hourly threshold for activating autophagy in humans. If you use this as a reason for a fasting pattern, be…
At what age does taking NAD+ supplements make sense?
There is no established age at which NAD+ supplementation becomes worthwhile; studies focus on middle-aged and older adults,…
Preliminary evidence
How does too much LDL or ApoB lead to clogged arteries?
Too many LDL and apoB particles sets off a well-established chain reaction that gradually clogs arteries. Having your apoB…
What is the relation between NAD+ and vitamin B3?
Vitamin B3 is the only dietary building block for NAD+ in your body -- that relationship is causal and well supported. Whether…
What is the controversy surrounding NAD+?
NAD+ supplements raise your NAD+ levels, but whether that translates into any health benefit has not been proven, and in the…
Does NAD+ cause weight gain?
There is no scientific evidence that NAD+ supplements such as NMN or NR cause weight gain. Animal research even suggests the…
No · Preliminary evidence
What are the effects if you take NAD every day?
Taking 600-900 mg of a NAD supplement per day raises your NAD levels and provides some benefit for endurance, but long-term…
Does coffee activate mTOR?
Caffeine inhibits mTOR in cell and animal research, but coffee as a complete drink actually activated mTOR in the muscle…
Chronic sleep deprivation: how harmful is it for weight and hormones?
Chronic sleep deprivation disrupts your hormones and metabolism after just a few nights. Structurally sleeping too little…
What is AMPK and how do you activate it (through fasting or exercise)?
Exercise and (short-term) fasting are the best-supported ways to activate AMPK, but whether every fasting or dietary strategy…
Yes · Moderate evidence
What does insulin do to the ageing process?
Chronically too much insulin is probably bad for healthy ageing, but science does not yet know precisely what the ideal…
Is yo-yo dieting, repeatedly gaining and losing weight, bad for me?
Yo-yo dieting carries real risks, particularly for cardiovascular health and psychological wellbeing, although some widely…
Yes · Moderate evidence
Does eating a lot of sugar give you type 2 diabetes?
Sugary drinks clearly and demonstrably increase your risk of type 2 diabetes. Sugar from solid food barely does. The biggest…
Does it make sense to limit blood sugar spikes, even without diabetes?
Limiting blood sugar spikes makes sense even without diabetes: the risk of cardiovascular disease appears to rise with spikes…
Yes · Moderate evidence
Why is it harder for me to lose weight than it used to be?
Ageing lowers your energy expenditure through muscle loss and a slower metabolism, making weight loss objectively harder.…
Does my metabolism really slow down as I get older?
Your resting metabolism really does decline with age, but the biggest culprit is muscle loss, not some mysterious metabolic…
Does it matter what time of day I eat?
Eating earlier in the day is more beneficial for your weight, blood sugar and hormonal balance than eating late or at night.…
Yes · Moderate evidence
Are smoothies and fresh juice just as healthy as whole fruit?
Whole fruit beats fruit juice: more fibre, greater satiety and fewer free sugars. Smoothies fall somewhere in between, but are…
No · Moderate evidence
Does the combination of glycine and NAC (GlyNAC) help against aging?
GlyNAC shows promising results in a small human study on oxidative stress, muscle function and inflammation, but the evidence…
Preliminary evidence
Does urolithin A from pomegranate do anything for your muscles and energy?
UA supplements (1000 mg/day) improve muscular endurance in older adults, but do not demonstrably increase total energy…
Moderate evidence
Does my weight and metabolism change during menopause?
During menopause, your body composition changes profoundly: more abdominal fat, less muscle and a lower resting metabolic…
Does losing weight noticeably improve my blood pressure and cholesterol?
Losing weight noticeably lowers your blood pressure and improves your cholesterol profile, but which value improves the most…
Yes · Strong evidence
What works better for weight loss: semaglutide or tirzepatide?
Tirzepatide consistently produces greater weight loss than semaglutide, but both medications have comparable gastrointestinal…
Yes · Strong evidence
Is my gut flora linked to being overweight?
Your gut microbiome is probably linked to excess weight through multiple mechanisms, but a proven causal relationship in…
Do you actually live longer if you structurally eat fewer calories?
In laboratory animals, eating less convincingly extends lifespan, but this has not yet been demonstrated for healthy people…
Moderate evidence
Does being overweight increase my risk of cancer, and if so, which types?
Excess weight increases your risk of at least 13 types of cancer, including uterine, colorectal, breast and liver cancer.…
What is a healthy HDL (good cholesterol) level, and can I raise it?
Raising HDL through lifestyle is possible, but your genes set the ceiling. Lowering triglycerides through less sugar and…
Moderate evidence
What is a healthy waist circumference and why does it matter?
A larger waist circumference is associated with a greater risk of diabetes, bone fractures, gum disease and premature death.…
What do artificial sweeteners do to your gut microbiome?
Whether artificial sweeteners truly disrupt your gut microbiome is not yet clear: studies contradict one another. Until there…
What is NAD+ and what does it do in your body?
NAD+ is an indispensable molecule for energy, DNA repair and cell health, but the question of whether you should actively…
Does berberine help against high blood sugar (the natural metformin)?
Be careful with this. Berberine measurably lowers blood sugar, but EFSA could not establish a safe intake level (signs of DNA…
Yes · Moderate evidence
How bad is fructose compared to regular sugar?
Fructose places a greater burden on the liver than glucose and raises triglycerides, belly fat and uric acid more. But regular…
How do I know if my blood sugar is healthy (prediabetes)?
Prediabetes can be measured reliably, but no single blood test provides complete certainty on its own. If in doubt, have…
I am overweight -- what will losing weight do for me?
Losing weight delivers measurable health gains from as little as 5% weight loss: better blood sugar, lower blood pressure and…
Does excess weight accelerate ageing?
Excess weight demonstrably accelerates biological ageing, but metabolic health counts at least as heavily as the number on the…
What is NAD+ and why does it decline as you age?
NAD+ is an indispensable energy carrier and guardian of your DNA, and your body produces less of it as you age. The mechanisms…
What does your thyroid do to your metabolism and energy?
Your thyroid is one of the most powerful regulators of your resting metabolism, and both too little and too much hormone has…
Do diabetes pills (SGLT2 inhibitors) also work against ageing?
For people with heart or kidney problems, large trials show that SGLT2 inhibitors clearly do more than lower blood sugar…
Moderate evidence
Does a walk after eating help with your blood sugar?
A short walk after eating, or better still several short walking breaks of 2 to 3 minutes spread throughout the day, is a…
Yes · Strong evidence
What is metabolic syndrome and how do I get rid of it?
Metabolic syndrome is a combination of abdominal fat, high blood pressure, disturbed blood sugar, and poor blood lipids, and…
Yes · Strong evidence
Is a glucose meter useful if you don't have diabetes?
Without diabetes, a glucose monitor gives you some genuinely interesting information about how your body responds to food,…
Preliminary evidence
What is insulin resistance and can I reverse it?
Insulin resistance can in many cases be substantially reversed, and exercising more combined with a healthier diet are the…
Yes · Strong evidence