Insulin resistance develops when tissues respond less effectively to insulin, driven largely by excess body weight and low-grade inflammation. For many people it can be substantially reduced or reversed through exercise, diet and medication if needed, although how far that is achievable depends on genetic and other individual factors.
Insulin resistance is a condition in which tissues such as muscle, liver and fat tissue respond less effectively to insulin, the hormone that regulates blood sugar. The pancreas tries to compensate by producing ever-increasing amounts of insulin. Over time that system becomes exhausted, blood sugar rises and type 2 diabetes can develop. Insulin resistance is therefore not a disease in itself, but an early signal that metabolism is falling out of balance (PMID 34965646, 37056675, 35794109, 40247011).
The main cause is excess body weight, and in particular dysfunctional fat tissue. When fat cells become too large, they release surplus fatty acids and inflammatory substances. Those fatty acids accumulate in the liver, muscles and pancreas ('ectopic fat') and disrupt insulin signalling in those organs. The liver is the most sensitive organ in this respect. In addition, chronic excess weight causes a smouldering low-grade inflammation across multiple organs, commonly referred to as 'metaflammation', which drives insulin resistance even further (PMID 33561645, 36230963, 21219177).
There is also a vicious cycle: high insulin levels resulting from insulin resistance can themselves worsen resistance to insulin further. The blood-sugar-lowering effect of insulin diminishes, while its fat-storage-promoting effect remains intact, causing the problem to reinforce itself (PMID 40247011). In addition, insulin resistance damages blood vessels: insulin normally promotes vessel dilation via nitric oxide, but that mechanism functions less well, leading to higher blood pressure and a greater risk of cardiovascular disease (PMID 33766485).
Good news: for many people, insulin resistance can be reversed or substantially reduced. Exercise and a healthier diet are by far the most well-evidenced approach, and are broadly supported by scientific research as the first step (PMID 37056675, 35794109, 34965646). Medications such as metformin and GLP-1 agonists (a newer class of drugs that also assist with weight loss) are effective pharmacological options, although no single medication has yet been officially approved with 'reversing insulin resistance' as a treatment indication (PMID 37056675, 35794109).
An important caveat: not everyone can fully reverse insulin resistance. Genetic predisposition, ageing, certain medical conditions, some medications and the composition of gut bacteria all play a role as well. This means that lifestyle improvements have a far greater effect in some people than in others. Reversing insulin resistance is therefore realistic for many, but not guaranteed for everyone (PMID 33561645, 37056675).
The claims used are based on multiple reviews and a meta-analysis (PMID 34965646, 37056675, 35794109, 40247011, 33561645, 36230963, 21219177, 33766485). The mechanistic basis for insulin resistance is strong; the treatment claims are based on reviews, not on individual RCTs within this set.