Browse evidence-based analysis of health-related claims and assertions
In obese animals, fat cells that don’t get enough oxygen may die or stop storing fat properly, causing more fatty acids to leak into the blood, which can interfere with insulin function.
Mechanistic
When fat cells don’t get enough oxygen, they make less of a helpful hormone called adiponectin that helps the body respond to insulin, which might make insulin resistance worse.
When fat tissue doesn't get enough oxygen in obese animals, it starts releasing inflammatory signals that may mess up the body's ability to use insulin properly.
When mice lack BAP31 and drink alcohol, their liver cells leak more enzymes into the blood, showing they’re more damaged.
Quantitative
When mice don’t have BAP31 and drink alcohol, their liver cells get overwhelmed with misfolded proteins, triggering a stress response that damages the cells.
When mice lack BAP31 and drink alcohol, their livers can’t store sugar properly, leading to low blood sugar and less energy for the body.
When mice don’t have the BAP31 protein and drink alcohol, their livers can’t fight off damaging free radicals as well, leading to more cell damage and signs of injury.
When mice lack a specific liver protein called BAP31 and drink alcohol, their livers store way more fat because they can't burn it off properly, making fatty liver disease worse.
Doing 8 weeks of strength training with your muscle either stretched or bunched up doesn’t make you much better at resisting fatigue — the improvement is very small and not clearly real.
Descriptive
When people train with their muscles stretched out, the longer their muscle fibers get, the more quickly they tire out during repeated efforts.
Correlational
When people train with their muscles bunched up, the more their muscle fibers angle upward, the longer they can keep pushing hard before getting tired.
Doing strength exercises with your muscle bunched up for 8 weeks can make the muscle fibers angle more sharply, which might help them generate more force.
Doing strength exercises with your muscle stretched out for 8 weeks can make the muscle fibers longer, but doing them with your muscle bunched up doesn’t change their length.
Most of the studies on this topic are not very well done—they often don’t report enough details, have small sample sizes, or use shaky methods, so we can’t trust their results fully.
Sometimes full-range lifting makes muscle fibers angle differently, which might mean they’re getting wider—but this change doesn’t really explain most of the muscle growth.
No one has actually counted the tiny units inside muscle fibers to see if full-range lifting adds more of them—so we don’t know if that’s really what’s happening.
Some studies say full-range lifting makes muscle fibers longer, but the tools used to measure this might be inaccurate, so we can’t be sure it’s really happening.
Working your muscles through a fuller range of motion during weight training might make them grow a little bigger than training with a shorter range, but it’s not always clear or the same for every muscle.
When people with low growth hormone take their hormone while fasting, their blood sugar goes up a little, but their body doesn’t use more or less glucose overall—so it’s just keeping sugar available without changing how it’s burned.
When people with low growth hormone take their hormone while fasting, their bodies burn more fat for energy instead of breaking down muscle.
When people with low growth hormone take their hormone while fasting, their bodies make less urea-N (a sign of protein being broken down), meaning they’re preserving their muscle and tissues better.
When people with low growth hormone fast and take their hormone, their bodies produce less urea (a waste product from breaking down protein), meaning they’re not losing as much protein.
When people with low growth hormone fast for a day and a half, giving them their hormone medicine helps their bodies keep building and keeping proteins instead of breaking them down.
Horses don’t grow new muscle cells as adults—they just make the ones they have bigger.