Can having too little body fat damage your bones?
Too little fat can damage your bones, but muscle mass and the location of fat matter at least as much. If you have concerns about bone health in combination with low body fat, discuss this with your general practitioner or sports medicine physician.
Having too little body fat can indeed damage your bones, but it is not as simple as 'more fat = better bones'. Which fat, where in the body, and how much muscle mass you have makes a big difference.
The clearest example comes from sports research. Among elite endurance athletes who were eating too little relative to their training load, 45% had reduced bone density. A quarter met all three criteria of the so-called 'female athlete triad': insufficient energy intake, disrupted menstruation, and weaker bones. Notably, these women were of normal weight. You do not have to be extremely thin to sustain bone damage.
Muscle mass probably plays a greater role in bone health than fat mass itself. Research in children showed that muscle was the only factor that predicted bone density. Greater fat mass in obese children was even associated with lower bone density in the spine. In postmenopausal women with diabetes, the group with insufficient muscle mass fared worst in terms of bone density, while excess weight without muscle loss appeared to actually protect the bones.
Not all fat does the same thing. Fat around the hips and thighs appears to protect the bones, even after correcting for other factors. Abdominal fat around the organs is associated with lower bone density in multiple studies, although causality has not yet been established here. The overall fat percentage therefore says little: the location of the fat matters.
At older ages, muscle loss and bone breakdown often occur together, sometimes combined with an increase or redistribution of fat mass. This interplay can negatively affect bone health. Low-grade chronic inflammation is considered a possible explanation, but the precise mechanisms have not yet been fully mapped out.
All claims are based on observational and associational research; one analysis using Mendelian randomisation provides some support for causality in the case of gynoid fat. No RCTs are available. Strength of evidence is predominantly moderate.
Does drinking a lot of alcohol weaken your bones?
Chronic heavy drinking demonstrably weakens your bones and substantially raises the risk of a hip fracture; for your bones there is no safe level above two drinks per day.
Does a vegetarian diet weaken your bones?
A vegetarian diet does not automatically weaken your bones, but as a vegan you need to pay extra attention to calcium and vitamin B12. Ensure adequate supplementation of both and the increased fracture risk can largely be prevented.
Is eating plant-based bad for your bones?
Eating strictly vegan is associated with lower bone density, but if you adequately supplement calcium and vitamin D, the elevated fracture risk largely disappears. As a vegan, also pay attention to vitamin B12, and discuss any supplement use with your GP or dietitian.
Do carbonated drinks damage your bones?
Regularly drinking large amounts of sugary carbonated drinks is associated with lower bone density, especially in women and during puberty. Moderate consumption appears less harmful, but it is preferable to replace soft drinks with beverages that support bone development.
Can statins (cholesterol-lowering medications) affect your bones?
Statins show positive effects on bone in laboratory and animal research, but randomised trials in humans do not confirm this. There is therefore no need to reconsider your cholesterol medication for the sake of your bones, but do not expect any bone protection from it either.
What happens to your bones when you lie in bed for a long time?
Prolonged bed rest demonstrably leads to substantial bone loss, particularly in the hip, spine and heel bone. Recovery takes much longer than the period of bed rest itself, so resuming movement as soon as possible is the best thing you can do.