| Cardio (moderate + intervals) | Do this | ●●●Strong | RCT / meta-analysis | Aerobic exercise ranks best for reducing body weight and BMI in overweight/obesity; HIIT is best for waist circumference. | Exercise-obesity NMA (opens in a new tab) |
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| Sleep duration | Watch this | ●●●Strong | RCT / meta-analysis | Short sleep raises obesity risk via lower leptin and higher ghrelin; about 1 h more sleep links to ~0.35 kg/m2 lower BMI. | Short sleep & central obesity meta (opens in a new tab) |
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| Strength (resistance) | Do this | ●●●Strong | RCT / meta-analysis | Resistance training lowers body-fat percentage and fat mass and best preserves/builds lean mass (raising resting metabolic rate); combined with aerobic is optimal. | Resistance training & body-composition meta (opens in a new tab) |
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| Sugary drinks & snacks — cut back | Do this | ●●●Strong | RCT / meta-analysis | Adding sugar-sweetened beverages caused +0.83 kg and removing them -0.49 kg, with a dose-response link to higher BMI and body weight. | SSB & weight meta (AJCN 2023) (opens in a new tab) |
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| Ultra-processed food — cut back | Do this | ●●●Strong | RCT / trial | An ultra-processed diet drove ~508 kcal/day more intake and weight gain vs a matched unprocessed diet; limiting ultra-processed foods helps prevent and treat obesity. | Hall et al. 2019, Cell Metabolism (opens in a new tab) |
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| Added Sugars | Don't overdo | ●●Moderate | RCT / meta-analysis | Excess added sugar, especially in liquid form, promotes weight gain through low satiety and incomplete calorie compensation. | SSB & weight meta (AJCN 2023) (opens in a new tab) |
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| Alcohol — cut back | Do this | ●●Moderate | RCT / meta-analysis | Heavy alcohol intake is associated with general and abdominal obesity (empty calories); light-moderate intake is inconsistent. | Alcohol & obesity meta (opens in a new tab) |
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| Anchor foods | Watch this | ●●Moderate | Review / narrative | Building meals around protein and fibre raises satiety hormones and diet-induced thermogenesis, curbing overall intake. | High-protein diet weight-loss review (opens in a new tab) |
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| Carbohydrate | Don't overdo | ●●Moderate | RCT / meta-analysis | Cutting refined/high-glycaemic carbohydrate lowers calorie intake and drives weight loss (low-carb diets reduce weight and BMI, especially short-term). Whole-food carbohydrates (vegetables, legumes, whole grains, fruit) are not the driver - refinement and total load are. | Low-carbohydrate diet weight-loss meta (Silverii 2022) (opens in a new tab) |
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| Cook real food | Do this | ●●Moderate | RCT / trial | Cooking minimally-processed meals lowers energy density and eating rate, reducing calorie intake compared with ultra-processed food. | Hall et al. 2019, Cell Metabolism (opens in a new tab) |
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| Daily movement baseline | Do this | ●●Moderate | RCT / meta-analysis | More everyday movement (NEAT) raises daily energy expenditure; adding activity to eating changes optimizes fat loss while sparing lean mass. | Exercise + caloric-restriction body-composition NMA (opens in a new tab) |
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| Movement (breaking up sitting) | Do this | ●●Moderate | Systematic review | Prolonged sitting relates to higher BMI; frequent breaks from sitting are linked to a more favourable body weight. | Sedentary behaviour & obesity review (opens in a new tab) |
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| Protein | Eat enough of | ●●Moderate | RCT / meta-analysis | Higher protein intake boosts satiety and diet-induced thermogenesis and preserves lean mass/resting metabolic rate, aiding weight loss and preventing regain. | High-protein diet weight-loss review (Wycherley meta) (opens in a new tab) |
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| Saturated fat | Don't overdo | ●●Moderate | RCT / trial | Energy-dense, saturated-fat-rich (often ultra-processed) foods drive excess calorie intake and weight gain. | Hall et al. 2019, Cell Metabolism (opens in a new tab) |
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| Screens before bed — cut back | Do this | ●●Moderate | RCT / trial | Genetic liability to TV and leisure screen time causally raises obesity risk (TV OR 1.55; leisure screen OR 1.62). | Sedentary behaviour & obesity MR (opens in a new tab) |
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| Sleep regularity | Watch this | ●●Moderate | RCT / meta-analysis | Irregular sleep timing / social jetlag is associated with ~23% higher odds of overweight/obesity via circadian misalignment. | "Association Between Social Jetlag and Components of Metabolic Syndrome: A Systematic Review and Meta-Analysis", 2024 (opens in a new tab) |
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| Total Fiber | Eat enough of | ●●Moderate | RCT / trial | High-fibre, minimally-processed diets promote satiety (PYY/GLP-1), lower energy density, and produce weight and fat loss. | High-fibre vs high-protein weight-loss trial (Te Morenga 2011) (opens in a new tab) |
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| Total Sugars | Don't overdo | ●●Moderate | RCT / meta-analysis | High free/added-sugar intake, especially from drinks and sweets, promotes weight gain; the intrinsic sugars in whole fruit and dairy are not implicated. | SSB & weight meta (AJCN 2023) (opens in a new tab) |
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| Water / hydration | Do this | ●●Moderate | RCT / meta-analysis | Replacing sugary drinks with water (or a pre-meal water load) lowers energy intake and supports weight loss. | SSB-to-water substitution meta (opens in a new tab) |
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| Calcium | Eat enough of | ●Emerging | RCT / meta-analysis | Dietary calcium, mainly from dairy, may modestly support fat oxidation and weight regulation; evidence is mixed. | Food groups & obesity dose-response meta (opens in a new tab) |
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| Colours a day | Watch this | ●Emerging | RCT / meta-analysis | Higher fruit and vegetable intake is modestly associated with less weight gain and lower adiposity risk (low energy density, satiety). | Fruit & vegetable intake & weight meta (opens in a new tab) |
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| Total Fat | Don't overdo | ●Emerging | RCT / trial | Fat is the most energy-dense macronutrient, so fat-rich (often ultra-processed) foods ease overeating; total fat itself is not uniquely fattening - saturated/trans fat and processing matter more. | Hall et al. 2019, Cell Metabolism (opens in a new tab) |
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| Iodine | Eat enough of | ●●●Strong | Established clinical | Iodine is the substrate for T3/T4; deficiency causes goiter, nodular disease and hypothyroidism. | Thyroid nutrition review (J Endocrinol Invest 2026) (opens in a new tab) |
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| Iodine | Don't overdo | ●●●Strong | Established clinical | Excess iodine (kelp/supplements) can precipitate hyperthyroidism or trigger autoimmune thyroiditis/hypothyroidism via thyrocyte ROS — the high end of the U-curve. | Thyroid nutrition review (J Endocrinol Invest 2026) (opens in a new tab) |
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| Selenium | Eat enough of | ●●●Strong | RCT / meta-analysis | Selenium powers deiodinases (T4→T3) and glutathione peroxidase; supplementation lowers TPO antibodies in Hashimoto’s. | Micronutrients & autoimmune thyroid review (PMC12372124) (opens in a new tab) |
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| Anchor foods | Watch this | ●●Moderate | Review / narrative | A Mediterranean-style pattern is associated with lower thyroid antibodies and inflammation in Hashimoto’s, supporting autoimmune thyroid function. | Micronutrients & autoimmune thyroid review (PMC12372124) (opens in a new tab) |
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| Colours a day | Watch this | ●●Moderate | Review / narrative | Dietary antioxidants help preserve thyrocyte oxidative status; oxidative stress and apoptosis are early triggers of autoimmune thyroid damage. | Minerals & autoimmune hypothyroidism review (PMC7574993) (opens in a new tab) |
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| Iron | Eat enough of | ●●Moderate | Review / narrative | Thyroid peroxidase is heme-dependent; iron deficiency is strongly associated with hypothyroid status and impairs hormone synthesis. | Minerals & autoimmune hypothyroidism review (PMC7574993) (opens in a new tab) |
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| Sleep duration | Watch this | ●●Moderate | Systematic review | Sleep normally inhibits TSH; sleep deprivation nearly doubles nocturnal TSH, and poor sleep is associated with subclinical hypothyroidism. | Thyroid & sleep patterns systematic review (PMC11285688) (opens in a new tab) |
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| Sleep regularity | Watch this | ●●Moderate | Systematic review | Night-shift/circadian disruption is associated with elevated TSH and higher rates of subclinical hypothyroidism — the clearest sleep-timing link to thyroid. | Shift-work & thyroid systematic review (PMC7084223) (opens in a new tab) |
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| Supplement discipline | Do this | ●●Moderate | Review / narrative | Iodine and selenium both follow a U-shape: repletion within the optimal window helps, but over-supplementation (especially iodine) can precipitate dysfunction — disciplined dosing matters. | Nutrition & thyroid myths/facts review (J Endocrinol Invest 2026) (opens in a new tab) |
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| Tobacco / vaping — quit | Do this | ●●Moderate | Review / narrative | Smoking interferes with iodide trapping at the Na⁺/I⁻ symporter and is linked to Graves’ disease and thyroid eye disease. | Diet in thyroid disorders review (PMC11451952) (opens in a new tab) |
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| Vitamin D | Eat enough of | ●●Moderate | Review / narrative | Vitamin D deficiency is far more common in Hashimoto’s/Graves’ patients and acts as an immunoregulatory factor in autoimmune thyroid disease. | Minerals & autoimmune thyroid review (PMC7574993) (opens in a new tab) |
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| Zinc | Eat enough of | ●●Moderate | Review / narrative | Zinc is required for thyroid hormone production and T3-receptor function; deficiency impairs thyroid metabolism. | Minerals & thyroid review (PMC7574993) (opens in a new tab) |
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| BMI | Watch this | ●Emerging | Cohort / observational | In ~5,000 adults with obesity, higher body weight (via visceral fat/leptin) predicted higher TSH within the normal range — excess weight nudges thyroid signalling upward. | Fontana et al., obesity–TSH cohort (PMC9606412) (opens in a new tab) |
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| Breath/mind (slow breathing) | Do this | ●Emerging | Review / narrative | Chronic stress activates the HPA axis and cortisol, which can disturb thyroid signalling; stress-reduction is a plausible support for autoimmune thyroid. | Thyroid & HPA/cortisol review (PMC11144793) (opens in a new tab) |
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| Cardio (moderate + intervals) | Do this | ●Emerging | Review / narrative | Moderate exercise favourably shifts immune balance (more T-regulatory cells) in autoimmune thyroid disease; excessive training can be counterproductive (J-curve). | Autoimmune thyroid & physical activity review (PMC12561809) (opens in a new tab) |
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| Copper | Eat enough of | ●Emerging | Review / narrative | Copper is among the trace minerals influencing thyroid hormone synthesis and regulation. | Nutrition & thyroid review (PMC11314468) (opens in a new tab) |
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| Daily movement baseline | Do this | ●Emerging | Review / narrative | Regular non-excessive activity beats sedentariness for autoimmune-thyroid outcomes and helps manage the weight/metabolic burden of hypothyroidism. | Autoimmune thyroid & physical activity review (PMC12561809) (opens in a new tab) |
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| Magnesium | Eat enough of | ●Emerging | Mechanistic | Magnesium supports the sodium-iodide symporter that maintains iodine supply for hormone synthesis. | Minerals & thyroid review (PMC7574993) (opens in a new tab) |
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| Protein | Eat enough of | ●Emerging | Mechanistic | Tyrosine, from dietary protein, is the amino-acid backbone of thyroid hormones. | Nutrition & thyroid review (PMC11314468) (opens in a new tab) |
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| Selenium | Don't overdo | ●Emerging | Review / narrative | Very high selenium risks selenosis and may adversely affect thyroid/metabolic markers — the top of selenium’s own U-shape. | Minerals & thyroid review (PMC7574993) (opens in a new tab) |
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| Sleep quality (refreshed) | Watch this | ●Emerging | Review / narrative | Poor sleep quality correlates with elevated TSH/T4 and, via HPA-axis/cortisol activation, can disturb the hypothalamic–pituitary–thyroid axis. | Thyroid dysfunction & sleep quality study (PMC11144793) (opens in a new tab) |
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| Ultra-processed food — cut back | Do this | ●Emerging | Review / narrative | Diet quality shapes the diet–gut–thyroid axis; poor patterns drive dysbiosis and micronutrient gaps that alter thyroid function. | Nutrition & thyroid narrative review (PMC11314468) (opens in a new tab) |
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| Vitamin A (RAE) | Eat enough of | ●Emerging | Review / narrative | Vitamin A participates in thyroid hormone metabolism and TSH regulation; low status is one micronutrient contributor to dysfunction. | Nutrition & thyroid review (PMC11314468) (opens in a new tab) |
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| Vitamin B12 | Eat enough of | ●Emerging | Review / narrative | B12 is commonly low in autoimmune thyroid disease (pernicious-anemia overlap); repletion supports Hashimoto’s patients. | Micronutrients & autoimmune thyroid review (PMC12372124) (opens in a new tab) |
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| Vitamin E | Eat enough of | ●Emerging | Review / narrative | Vitamin E’s antioxidant action is among the nutrient factors examined for protecting thyrocytes in hypothyroidism/Hashimoto’s. | Micronutrients & autoimmune thyroid review (PMC12372124) (opens in a new tab) |
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| BMI | Watch this | ●●●Strong | Review / narrative | Excess weight, especially central (visceral) fat, is the primary driver of insulin resistance; losing weight can push type 2 diabetes into remission. | Diet & T2D prevention (Lancet) (opens in a new tab) |
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| Body Roundness Index | Watch this | ●●●Strong | Review / narrative | Body-shape indices reflecting central adiposity track insulin resistance and metabolic-syndrome risk better than weight alone. | Diet & T2D prevention (Lancet) (opens in a new tab) |
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| Cardio (moderate + intervals) | Do this | ●●●Strong | RCT / meta-analysis | All exercise lowers HbA1c; interval and aerobic training are most effective, improving insulin sensitivity and skeletal-muscle glucose uptake. | Exercise modalities & HbA1c (NMA) (opens in a new tab) |
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| Magnesium | Eat enough of | ●●●Strong | RCT / meta-analysis | Higher magnesium intake is inversely associated with type 2 diabetes (per 500 mg/day OR ~0.62); magnesium is a cofactor for insulin signalling. | Glycemic index, fiber, magnesium & T2D (opens in a new tab) |
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| Magnesium | Eat enough of | ●●●Strong | RCT / meta-analysis | Higher magnesium intake is inversely associated with type 2 diabetes (per 500 mg/day OR ~0.62); magnesium is a cofactor for insulin signalling. | Association of magnesium intake with type 2 diabetes and total stroke: an updated systematic review and meta-analysis, BMJ Open 2020 (opens in a new tab) |
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| Sleep duration | Watch this | ●●●Strong | RCT / meta-analysis | Short sleep (under 6 h vs 7 h) raises type 2 diabetes risk ~30% via insulin resistance, cortisol and appetite-hormone disruption. | Short sleep & T2D meta (opens in a new tab) |
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| Strength (resistance) | Do this | ●●●Strong | RCT / meta-analysis | Resistance training lowers HbA1c (~0.8%) by expanding muscle glucose-storage capacity and enhancing insulin signalling (IRS-1/PI3K/Akt). | Resistance training & HbA1c meta (opens in a new tab) |
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| Sugary drinks & snacks — cut back | Do this | ●●●Strong | RCT / meta-analysis | Sugar from beverages (sugary drinks, fruit juice) raises type 2 diabetes risk, while total dietary sugar does not - the beverage form is the key harm. | Dietary sugar & T2D meta (opens in a new tab) |
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| Total Fiber | Eat enough of | ●●●Strong | RCT / meta-analysis | Higher fiber intake, especially cereal fiber, lowers type 2 diabetes risk and improves glycemic control by slowing glucose absorption. | Diet & T2D prevention (Lancet) (opens in a new tab) |
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| Total Fiber | Eat enough of | ●●●Strong | RCT / meta-analysis | Higher fiber intake, especially cereal fiber, lowers type 2 diabetes risk and improves glycemic control by slowing glucose absorption. | Dietary fibre and incidence of type 2 diabetes in eight European countries: the EPIC-InterAct study, Diabetologia 2015 (opens in a new tab) |
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| Ultra-processed food — cut back | Do this | ●●●Strong | RCT / meta-analysis | Higher ultra-processed food intake raises type 2 diabetes risk dose-dependently, independent of BMI and overall diet quality. | Ultra-processed food & T2D meta (opens in a new tab) |
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| Waist-to-height ratio | Watch this | ●●●Strong | Review / narrative | Increased waist circumference (visceral fat) marks high type 2 diabetes risk; waist-based ratios are core metabolic-syndrome criteria and drive insulin resistance. | Prevention and management of type 2 diabetes: dietary components and nutritional strategies (Lancet) (opens in a new tab) |
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| Waist-to-hip ratio | Watch this | ●●●Strong | Review / narrative | Visceral fat (high waist-to-hip ratio) releases free fatty acids and inflammatory adipokines that cause insulin resistance; central to metabolic syndrome. | Diet & T2D prevention (Lancet) (opens in a new tab) |
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| Added Sugars | Don't overdo | ●●Moderate | RCT / meta-analysis | Added sugar raises diabetes risk mainly through sugary beverages; total added sugar in aggregate shows little independent effect - the beverage form is the harm. | Dietary sugar & T2D meta (opens in a new tab) |
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| Anchor foods | Watch this | ●●Moderate | Review / narrative | Building meals around fiber, protein and low-glycemic foods blunts glucose spikes and improves glycemic control. | Diet & T2D prevention (Lancet) (opens in a new tab) |
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| Carbohydrate | Don't overdo | ●●Moderate | Cohort / observational | Carbohydrate quality is what matters: high-glycemic-index and refined starch raise diabetes risk (GI OR ~1.32, starch OR ~1.47), whereas total and whole-food carbohydrate do not. | Glycemic index & refined starch & T2D (opens in a new tab) |
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| Colours a day | Watch this | ●●Moderate | Review / narrative | Diets rich in vegetables, fruit, legumes and whole grains lower diabetes risk through fiber and polyphenols. | Diet & T2D prevention (Lancet) (opens in a new tab) |
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| Cook real food | Do this | ●●Moderate | RCT / meta-analysis | Cooking real food instead of ultra-processed products cuts refined starch, added sugar and additives linked to diabetes. | Ultra-processed food & T2D meta (opens in a new tab) |
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| Daily movement baseline | Do this | ●●Moderate | RCT / meta-analysis | Even physical-activity advice and daily movement improve glycemic control; replacing sedentary time helps. | Physical activity & glycemic control (opens in a new tab) |
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| Movement (breaking up sitting) | Do this | ●●Moderate | RCT / meta-analysis | Breaking up prolonged sitting with brief activity lowers post-meal glucose and reduces diabetes risk. | Physical activity & glycemic control (opens in a new tab) |
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| Saturated fat | Don't overdo | ●●Moderate | Review / narrative | Replacing saturated fat with unsaturated fat improves insulin sensitivity and lowers diabetes risk; refined-carb plus saturated-fat patterns worsen it. | Diet & T2D prevention (Lancet) (opens in a new tab) |
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| Sleep quality (refreshed) | Watch this | ●●Moderate | RCT / meta-analysis | Poor sleep quality and fragmentation (including sleep apnea) worsen insulin sensitivity and raise diabetes risk. | Sleep & T2D risk meta (opens in a new tab) |
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| Sleep regularity | Watch this | ●●Moderate | RCT / meta-analysis | Irregular sleep and circadian misalignment (evening chronotype, shift work) raise diabetes risk independent of sleep length. | Sleep features & T2D meta (opens in a new tab) |
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| Tobacco / vaping — quit | Do this | ●●Moderate | Cohort / observational | Smoking directly causes insulin resistance and raises type 2 diabetes risk ~30-40%; it also increases central adiposity. | Tobacco, insulin resistance & T2D (opens in a new tab) |
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| Total Sugars | Don't overdo | ●●Moderate | RCT / meta-analysis | Dietary sugar raises diabetes risk when consumed as beverages; total and naturally-occurring sugars (fruit, dairy) show null or inverse associations. | Dietary sugar & T2D meta (opens in a new tab) |
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| Trans fat | Don't overdo | ●●Moderate | Cohort / observational | Partially hydrogenated (trans) fats, concentrated in ultra-processed foods, are linked to higher type 2 diabetes risk. | Ultra-processed food & T2D cohorts (opens in a new tab) |
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| Vitamin D | Eat enough of | ●●Moderate | RCT / meta-analysis | Low vitamin D status is associated with higher type 2 diabetes risk; supplementation in prediabetes gives modest benefit. | Diet & T2D prevention (Lancet) (opens in a new tab) |
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| Zinc | Eat enough of | ●●Moderate | RCT / meta-analysis | Zinc supplementation improves glycemic markers (HbA1c, fasting glucose, insulin resistance); zinc stabilizes insulin and is anti-inflammatory. | Zinc & glycemic biomarkers meta (opens in a new tab) |
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| Alcohol — cut back | Do this | ●Emerging | RCT / meta-analysis | Alcohol has a J-shaped link to diabetes: moderate intake may lower risk while heavier drinking reduces insulin sensitivity and raises it. | Alcohol & T2D (J-shaped) (opens in a new tab) |
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| Alcohol — cut back | Do this | ●Emerging | RCT / meta-analysis | Alcohol has a J-shaped link to diabetes: moderate intake may lower risk while heavier drinking reduces insulin sensitivity and raises it. | "Association between alcohol consumption and the risk of incident type 2 diabetes: a systematic review and dose-response meta-analysis", Am J Clin Nutr 2016 (opens in a new tab) |
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| Chromium | Eat enough of | ●Emerging | RCT / trial | Chromium supplementation shows modest, inconsistent glycemic benefit (~-0.6% HbA1c in one review), mainly at high doses; evidence is mixed. | Chromium & glucose metabolism (opens in a new tab) |
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| Loneliness — reduce | Watch this | ●Emerging | RCT / meta-analysis | Loneliness is associated with ~32% higher type 2 diabetes risk, plausibly via chronic stress and unhealthy behaviours. | Loneliness & T2D incidence meta (opens in a new tab) |
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| Sodium | Don't overdo | ●Emerging | Cohort / observational | High sodium intake is one mediator of the ultra-processed-food link to type 2 diabetes and clusters within metabolic syndrome. | Ultra-processed food & T2D cohorts (opens in a new tab) |
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| Water / hydration | Do this | ●Emerging | RCT / meta-analysis | Choosing water over sugary drinks removes the main beverage-sugar driver of diabetes risk. | Dietary sugar & T2D meta (opens in a new tab) |
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