There is not a lot research (yet) on micro or nanoplastics or nanomaterials and diabetes or obesity, but the research field is beginning to grow. There are over 80 studies, actually, if you include fatty liver disease.
Did you know that drinking water bottled in plastic is linked to an increased risk of diabetes? Perhaps due to the microplastics in the water... (Dolcini et al. 2024). Bottled water is also linked to an increased risk of fatty liver (Xu et al. 2025).
Or it could be the chemicals in the plastic: Mice fed with a diet heated in two types of polypropylene plastic food containers had accelerated body weight gain, altered fasting blood glucose levels, and other metabolic changes (Liu et al. 2025). Environmental chemicals attach to micro and nano plastics. The combination of exposure may be more harmful than exposure to either alone.
We don't really know yet if it's the plastic particles or the chemicals in the plastics that cause health effects, but a few studies (not related to diabetes so far) are pointing to the chemicals.
An article summarizes evidence that finds that "there is sufficient evidence to suggest that bisphenols, a group of common chemicals found in plastics, may contribute to an increased risk of obesity and diabetes in human cohorts." (Nadal, 2025).
A review states, "While experimental studies have demonstrated that MNPs disrupt glucose metabolism, insulin signaling, and lipid homeostasis through oxidative stress, systemic inflammation, and endocrine disruption, the implications for human health remain largely unexplored." (Shruti et al. 2025).
A summary concludes that, "animal studies provide strong evidence of the impacts of microplastics and nanoplastics exposure on glycolysis, blood glucose levels, insulin secretion, and insulin resistance." (Hsiao et al. 2025).
A review finds evidence that micro and nano plastics could contribute to diabetes, obesity, insulin resistance, and fatty liver, and affect the gut microbiota (Zheng et al. 2024).
A review notes that new research on micro- and nano-plastics can cause insulin resistance and impaired glucose metabolism in laboratory studies (Barbieri et al. 2024).
A review finds that nanoplastics can enter the gut and disturb the gut microbiome, and have heath effects related to diabetes and obesity (Haldar et al. 2023).
A review notes, "Recently, some studies have raised concerns about the possible detrimental effects of TiO2 nanoparticles on glucose homeostasis (Mohammadparast and Mallard, 2022). Another review finds that these particles may also affect the gut microbiota and contribute to obesity (Lamas et al. 2023).
A review finds that laboratory animals exposed to microplastics and their additives develop inflammation, immunological responses, endocrine disruption, and alterations in energy metabolism; microplastics are potential obesogens, and could promote non-alcoholic fatty liver disease (NAFLD) by modifying gut microbiota composition (Auguet et al. 2022).
A review finds that both nano- and micro-plastics can disturb the gut microbiota and intestinal barrier, and affect the immune system (Hirt and Body-Malapel 2020). (Changes to the gut microbiota and gut barrier are linked to type 1 diabetes; see the Diet and the Gut page).
An older review looks at diabetes and engineered nanomaterials (Priyam et al. 2018).
There are not many studies yet on microplastics in humans. One, however, did find that microplastics may affect the gut microbiota in Chinese preschoolers (Ke et al. 2023). Another found that Chinese college students who ate more take-out food had higher levels of microplastics in their stool, different microbiota, and higher BMI (Hong et al. 2024).
A study from Canada was done in people who had bariatric surgery for obesity. They found links between fecal microplastic levels and immune system markers, fecal microbiota, and persistent fatty liver disease post-surgery, among other things (Schwenger et al. 2024).
Microplastics
Animal studies find that exposure to microplastics can cause:
higher blood glucose levels ( Li et al. 2024; Okamura et al. 2023; Shi et al. 2022; Xu et al. 2024; Zhai et al. 2024), including beta cell death in combination with phthalates (Wang et al. 2022).
higher insulin levels (Saeed et al. 2023).
glucose intolerance (Li et al. 2024; Saeed et al. 2023), including in combination with lead (Zhu et al. 2024).
insulin resistance (Huang et al. 2022; Roh et al. 2024; Shi et al. 2022), including in combination with lead (Zhu et al. 2024).
increased body weight (Huang et al. 2023; Muhammad et al. 2023; Xu et al. 2024; Zhai et al. 2024; Zhao et al. 2024).
changes to cholesterol or triglyceride levels (Chiu et al. 2025; Okamura et al. 2023; Saeed et al. 2023; Tao et al. 2024; Zhou et al. 2023).
changes to the gut microbiota (Huang et al. 2022; Kou et al. 2025; Li et al. 2025; Lu et al. 2025; Medriano and Bae, 2022; Muhammad et al. 2023; Wei et al. 2025; Zhang et al. 2023; Zhai et al. 2024; Zhou et al. 2023), including in combination with PFAS (Jiang et al. 2025) or pesticides (Fang et al. 2025).
intestinal inflammation or injury (Okamura et al. 2023; Shi et al. 2022; Wei et al. 2025; Zhang et al. 2023; Zhou et al. 2023), including in combination with PFAS (Jiang et al. 2025).
fatty liver or liver injury (Du et al. 2023; Li et al. 2024; Lu et al. 2025; Okamura et al. 2023; Roh et al. 2024; Wei et al. 2025; Zhai et al. 2024), including in combination with PFAS (Jiang et al. 2025).
Interactions with other factors
Some studies found that the metabolic effects of microplastics occurred only on a high-fat diet (e.g., Okamura et al. 2023; Xu et al. 2024) or that a high-fat diet and microplastics interacted to exacerbate the effects (e.g. Du et al. 2023; Wei et al. 2025).
Mice with diabetes were more susceptible to the health effects of polystyrene microplastics than mice without diabetes (Liu et al. 2022).
Aged microplastics have more disruptive metabolic effects than pristine microplastics, although both have some effects (Cui et al. 2025); however another study found that pristine were worse than aged (Liu et al. 2024).
The metabolic effects of microplastics were reduced by an compound found in berries (Zhao et al. 2024).
A computer-based analysis looked at how microplastics may exacerbate diabetic kidney disease (Zeng and Guo, 2025).
Nanoplastics
Animal studies find that nanoplastics can cause:
higher blood glucose levels (Das et al. 2025; Fan et al. 2021; Wang et al. 2024; Wang et al. 2023; Yang et al. 2024), including in combination with PFAS (Zhang et al. 2025).
glucose intolerance (Wang et al. 2024; Wang et al. 2023; Yang et al. 2024).
insulin resistance (Fan et al. 2024; Fan et al. 2021; Wang et al. 2024; Wang et al. 2023; Yang et al. 2024; Zhang et al. 2024).
increased body weight/fat mass (Chen et al. 2025; Muhammad et al. 2023; Zhang et al. 2024).
higher cholesterol or triglyceride levels (Chen et al. 2025; Das et al. 2025; Fan et al. 2021).
changes to the gut microbiota (Muhammad et al. 2023; Zhang et al. 2023).
gut barrier permeability and/or inflammation (Kim et al. 2024; Shiu et al. 2022; Zhang et al. 2023).
fatty liver or liver injury (Lu et al. 2024; Shi et al. 2025; Shiu et al. 2022; Susilo et al. 2025; Xu et al. 2025; Yu et al. 2024; Zhang et al. 2024).
Interactions with other factors
The effects were lessened by antioxidants (Zhang et al. 2024).
The obesogenic effects of nanoplastics occurred without increased food intake (Chen et al. 2025).
Nanomaterials
Animal studies find that nanomaterials/nanoparticles can cause:
higher blood glucose levels (Abdel Aal et al. 2020; Ali 2019).
changes in cholesterol or triglyceride levels (Ali 2019).
changes to the gut microbiota (Perez et al. 2021).
changes linked to diabetes and metabolic syndrome (Guo et al. 2019).
Exposure during development
Animal studies find that exposure to micro/nanoplastics or nanoparticles during in utero or early life development can cause (in offspring):
higher blood glucose levels (Kim et al. 2025; Tiwari et al. 2021).
increased body weight (Jeong et al. 2024; Kim et al. 2025).
changes to cholesterol or triglyceride levels (Chen et al. 2022; Lu et al. 2024; Luo et al. 2019b; Zhao et al. 2021).
brown fat tissue whitening (Shen et al. 2025).
changes to the gut microbiota (Jeong et al. 2024; Zhao et al. 2021).
intestinal barrier damage (Lu et al. 2024).
fatty liver or changes to liver (Lu et al. 2024; Luo et al. 2019a; Xin et al. 2024).
And in the animal mothers caused:
insulin resistance and/or high glucose levels (Chen et al. 2021; Mao et al. 2019; Zhang et al. 2024).
metabolic disorders, changes to the gut microbiota, and/or gut barrier dysfunction (Luo et al. 2019a), including in combination with BPA (Liu et al. 2025).
Additional generations
Developmental exposure to micro or nanoplastics caused metabolic disorders in both the first and second generation offspring (Luo et al. 2019a), including in combination with BPA (Liu et al. 2025).
Cell studies
Beta cells
Microplastics and phthalates combined synergistically to cause beta cell death (Wang et al. 2022).
Fat cells
Microplastic extracts from Italian waters affected fat cell metabolism (Capriotti et al. 2020).
Microplastics promote fat cell aging (Moon et al. 2024).
Liver cells
Nanoplastics, especially aged ones, affected glucose metabolism in liver cells (Wang et al. 2025).
Bio-based microplastics
Bioplastics are often seen as one solution to the plastics crisis. However, that may not be the case. Starch-based microplastics can infiltrate the mouse liver and intestine, and cause high blood glucose levels and insulin resistance (Liu et al. 2025).
To download or see a list of all the references cited on this page, see the collection Microplastics and diabetes/obesity in PubMed.