Browse the evidence

Deletion of intestinal epithelial MyD88 in mice prevents diet-induced obesity and metabolic disorders by increasing energy expenditure and improving gut barrier function, an effect mediated by changes in gut microbiota composition.

This research suggests that the health of your intestinal lining and its interaction with gut bacteria play a critical role in whether your body stores fat or burns energy, especially when eating a high-fat diet. While this study used genetic modification in mice, it implies that maintaining gut barrier integrity and a healthy microbiome might be key strategies for preventing obesity-related metabolic issues.

Targeting intestinal epithelial MyD88 therapeutically reduces fat mass and inflammation even after obesity is established, suggesting a potential treatment for existing obesity.

This study suggests that even after obesity develops, interventions that support intestinal health and reduce inflammation might help reverse fat gain. For now, this translates to focusing on dietary patterns that support gut barrier integrity and a diverse microbiome, rather than waiting for specific pharmaceutical targets.

During acute respiratory viral infections (RVIs), specific lipid subclasses (small TAGs, LPCs, ether-linked PEs) undergo dynamic, phase-dependent changes that correlate with immune response and energy metabolism shifts.

Your lipid profile is not static during illness. Small TAGs drop sharply early in infection (possibly for energy), while LPCs and ether-linked PEs drop later, correlating with inflammation. This suggests lipids play an active role in managing the immune response and energy demands of acute illness, rather than just being passive storage molecules.

Aging causes a progressive decline in mitochondrial reserve respiratory capacity (RRC), which sensitizes high-energy tissues (brain, heart, skeletal muscle) to bioenergetic exhaustion and increases the risk of age-related pathologies and cell death.

Your body's ability to handle sudden energy demands (like intense exercise or stress) declines with age because your mitochondria produce less 'spare' energy. This makes you more vulnerable to fatigue and tissue damage. However, in skeletal muscle, this decline is not permanent; regular endurance exercise can restore mitochondrial content and function, effectively rebuilding this safety margin.

Weight loss therapies, including bariatric surgery and hypocaloric diets, inevitably lead to skeletal muscle catabolism, particularly during rapid weight loss phases.

When you start a diet or surgery, expect some muscle loss. To protect your muscle, ensure you eat enough protein and engage in resistance training, as rapid weight loss makes muscle loss more likely.

SGLT2 inhibition induces a fasting-like metabolic state characterized by increased fatty acid oxidation, ketogenesis, and reduced hepatic steatosis independently of FGF21.

SGLT2 inhibitors shift the body's fuel source to fat and ketones, mimicking a fasting state. This metabolic switch occurs even if the hormonal pathway for fat loss (FGF21) is blocked.

Isocaloric substitution of added sugars (sucrose or HFCS) for other carbohydrates does not increase risk factors for obesity, type 2 diabetes, or cardiovascular disease in adults.

If you consume added sugars within your daily calorie needs, replacing them with other carbohydrates (like starch) will not improve your metabolic health markers (weight, blood sugar, lipids) any more than keeping them would. The key is total energy balance, not the specific source of calories, unless you are consuming excessive amounts that lead to a caloric surplus.

Rapid urbanization and globalization in South Africa drive a nutritional transition characterized by increased consumption of high-fat, high-sugar processed foods and decreased physical activity, leading to a significant rise in obesity prevalence across all demographic groups.

To combat obesity in urbanizing environments, policy and individual actions must focus on modifying the food environment (limiting access to cheap, high-fat processed foods) and increasing opportunities for physical activity, rather than relying solely on individual willpower.

Continued global nutrition transition toward high animal-source food and empty calorie consumption will result in 45% of the world population being overweight and 16% obese by 2050, driving a 50% increase in global food demand.

To avoid the projected 45% overweight rate by 2050, individuals and policymakers must prioritize reducing household food waste and shifting dietary composition away from animal-source foods and empty calories. This involves increasing consumption of vegetables, fruits, and nuts, and recognizing that current trends are unsustainable for both health and the environment.

Liraglutide treatment does not significantly alter 24-hour energy expenditure or substrate oxidation in patients with type 2 diabetes.

Taking liraglutide will not change how many calories you burn throughout the day. Your energy expenditure remains the same as if you were taking a placebo.

High levels of daily physical activity in hunter-gatherer populations do not result in higher total energy expenditure (TEE) compared to industrialized populations, as the body compensates by reducing non-exercise activity thermogenesis (NEAT) and resting metabolic rate (RMR).

Do not rely on exercise alone to create a massive caloric deficit, as your body may compensate by lowering its resting metabolic rate. Focus on dietary quality and portion control, as high activity levels alone may not increase total energy expenditure significantly enough to drive weight loss if diet is not managed.

GIPR antagonism reduces the Respiratory Exchange Ratio (RER) during rest, indicating increased lipid oxidation as a mechanism for weight loss.

Blocking GIP receptors may help your body burn more fat for fuel while at rest, even without changing your activity level. This metabolic shift contributes to the overall weight loss observed.

Mitochondrial dysfunction in white adipose tissue, characterized by reduced biogenesis and oxidative capacity, is a key factor in the development of obesity and insulin resistance.

If you struggle with obesity or insulin resistance, consider that your fat cells' mitochondria may be dysfunctional. Improving mitochondrial health through regular exercise and potentially cold exposure can help restore normal metabolic function and support weight loss efforts.

In adult mice with progressive AgRP neuron degeneration, de novo neurogenesis in the hypothalamus serves as a compensatory mechanism to maintain energy balance; blocking this proliferation causes significant decreases in food intake and body adiposity.

This research suggests that the brain has a built-in repair mechanism for energy regulation when specific hunger-signaling neurons are lost. While this doesn't translate to a direct intervention for healthy people yet, it highlights the hypothalamus's plasticity. For now, maintaining metabolic health through diet and exercise remains the primary way to support these systems, as the paper shows that blocking natural cell proliferation leads to weight loss and reduced food intake in compromised models.

Metabolic health is determined by the capacity of adipose tissue to expand (adipose expandability) rather than absolute fat mass; when this capacity is exceeded, ectopic fat accumulation and insulin resistance occur.

Focus on maintaining healthy fat distribution and avoiding excessive caloric overload that exceeds your body's ability to store fat safely, rather than solely targeting weight loss numbers.

Using alternative methods to account for dietary misreporting (specifically revised Goldberg and predicted total energy expenditure methods) strengthens and clarifies the associations between dietary intake and body mass index compared to the original Goldberg method.

When analyzing diet and weight data, do not rely solely on standard energy reporting cutoffs. Use alternative methods like predicted total energy expenditure (pTEE) or revised basal metabolic rate equations to identify and account for misreporting. This approach strengthens the observed associations between diet and BMI, providing more accurate insights into how specific foods impact weight.

In older adults and those with insulin resistance, brain glucose uptake is significantly reduced (hypometabolism) in specific regions (frontal, temporal, parietal cortex), creating an energy deficit that precedes cognitive decline and Alzheimer's Disease.

If you are over 65 or have metabolic risk factors like insulin resistance, your brain may be using less glucose even if your memory seems fine. This 'energy deficit' is a known precursor to cognitive decline. While this paper doesn't prescribe a fix, it highlights that maintaining metabolic health (managing blood sugar/insulin) is critical for brain fuel supply in later life.

Ketone bodies (beta-hydroxybutyrate and acetoacetate) serve as an effective alternative fuel for the brain in aging and Alzheimer's Disease because ketone uptake remains normal even when glucose uptake is impaired.

Your brain can switch to burning ketones for fuel even if you have early Alzheimer's or cognitive decline. This metabolic flexibility exists, which is why strategies that raise ketone levels (like ketogenic diets or MCT oil) are being explored to support brain function in aging.

Activation of AMPK by dietary restriction or compounds like metformin extends lifespan by inhibiting mTOR and promoting mitochondrial biogenesis.

Dietary restriction activates AMPK, which improves mitochondrial health and extends lifespan. If strict dieting is not feasible, compounds like metformin (which activate AMPK) or time-restricted eating may offer similar metabolic benefits.

Gut microbiota depletion via broad-spectrum antibiotics significantly reduces skeletal muscle endurance and fatigue resistance in healthy mice, an effect mediated by altered glucose homeostasis and muscle glycogen levels rather than changes in muscle mass or mitochondrial function.

Maintaining a healthy gut microbiome is important for muscle endurance. While this study used mice, it suggests that factors disrupting gut bacteria (like broad-spectrum antibiotics) may temporarily reduce your stamina and fatigue resistance. Restoring gut health (natural reseeding) can reverse these effects. Focus on fiber-rich foods and fermented foods to support gut bacteria, which may help optimize glucose availability for your muscles during exercise.

Dietary restriction (DR) extends lifespan and healthspan in model organisms, but its impact on skeletal muscle mass is complex, potentially attenuating age-related loss in some species while causing absolute mass decrease in others.

Dietary restriction is the most reliable way to extend lifespan in animals. In rats and monkeys, it also helps preserve muscle mass by reducing inflammation and oxidative stress. For humans, this suggests that moderate caloric restriction, combined with resistance training and adequate protein, might help maintain muscle function and healthspan, even if it doesn't maximize muscle size. The focus should be on nutrient density and metabolic health rather than just caloric deficit.

Decreased mitochondrial biogenesis and dysregulated lipid oxidation lead to compromised skeletal muscle bioenergetic status (low ATP) and muscle wasting in early critical illness.

Early muscle loss in the ICU is driven by a failure of the muscle's energy factories (mitochondria) to produce ATP, not just by lack of movement. This metabolic shutdown prevents recovery even if nutrition is provided.

In individuals with type 2 diabetes, hepatic energy metabolism (specifically ATP and inorganic phosphate concentrations) is impaired and correlates with hepatic insulin resistance, independent of liver fat content.

For those with Type 2 Diabetes, liver health involves more than just fat storage; it involves cellular energy production. Research indicates that even when liver fat levels are similar to non-diabetics, people with T2DM have significantly lower levels of cellular energy (ATP) in the liver, which drives insulin resistance. This suggests that supporting mitochondrial health and energy metabolism is a key target for managing T2DM, potentially preceding or existing independently of visible liver fat.

Physical activity level (PAL) in humans is biologically constrained, with a maximum sustainable value of approximately 2.0-2.5, meaning energy intake, not just activity, drives obesity trends.

You cannot simply 'out-exercise' a poor diet because your body has a hard limit on how much energy you can burn through daily activity (max PAL ~2.5). Since energy expenditure doesn't scale infinitely with activity, managing energy intake is the critical lever for body mass regulation.