In obese adults, reducing calorie intake by 20-30% for 12 to 16 weeks changes epigenetic markers in fat tissue, including DNA methylation and histone modifications, and alters the levels of specific...
Mechanism
Synthesis from 1 study
Eating fewer calories tells fat cells to change how they read their genes—turning on fat-burning and energy-making genes while turning off inflammation signals. This happens through chemical switches on the DNA and its packaging, which make the good genes easier to use and the bad ones harder to...
Most probable mechanism
When a person eats significantly fewer calories, their fat cells sense the drop in energy and change how their genes are read without changing the DNA itself. This happens by removing chemical tags that silence metabolic genes, adding tags that turn genes on, and reducing tiny molecules that block fat-burning processes. As a result, fat cells start breaking down fat more efficiently, produce more energy-making machinery, and stop releasing inflammatory signals, which helps the body respond better to insulin and lowers overall inflammation.
Reduced calorie intake lowers the availability of methyl-donor nutrients, decreasing the activity of enzymes that add methyl groups to DNA.
This leads to hypomethylation at the promoters of metabolic genes such as PPARG and IRS1, increasing their accessibility for transcription.
Calorie restriction elevates cellular NAD+ levels, activating a deacetylase enzyme that removes acetyl groups from histones at inflammatory gene loci.
Simultaneously, activating histone marks such as H3K9ac and H3K4me3 increase at promoters of mitochondrial and insulin-signaling genes, while repressive marks like H3K27me3 decrease.
These combined epigenetic changes create a permissive chromatin environment that enhances transcription of genes involved in lipid oxidation, mitochondrial biogenesis, and insulin sensitivity.
Expression of microRNAs that suppress lipid catabolism and adipocyte maturation, such as miR-27a and miR-34a, is reduced, relieving inhibition of their target mRNAs.
Increased lipid breakdown and mitochondrial activity reduce ectopic fat accumulation and improve cellular energy efficiency.
Suppression of pro-inflammatory gene expression in adipose tissue reduces the release of cytokines into circulation, lowering systemic inflammation.
Improved insulin signaling and reduced inflammation collectively enhance whole-body insulin sensitivity.
Evidence from Studies
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