Here you go: A comprehensive definition for metabolic syndrome https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2675814/ - see Table 1 as the definition can vary, but NCEP ATP III is 3/5 of central obesity, fasting glucose (or high HbA1c), >150 mg/dl of TG, <40 mg/dl(M) <50 mg/dl(F) HDL, >130/85 mmHg blood pressure.
The guidelines they used were (very similar but slightly more stringent than the ATP III):
* waist circumference (WC <102/88 cm for men/women)
* glucose (fasting glucose <100 mg/dL and hemoglobin A1c <5.7%)
* blood pressure (systolic <120 and diastolic <80 mmHg)
* triglycerides (<150 mg/dL)
* high-density lipoprotein cholesterol (≥40/50 mg/dL for men/women)
* not taking any related medication
Even w/ ATP III, only 19.9% of American adults don't have metabolic syndrome.
What metabolic syndrome really is, is hyperinsulinemia/insulin resistance. You should get your estimates by having fasting glucose and fasting insulin tested for to get HOMA-IR and QUICKI estimates (TG-FB and TC/HDL are two other estimates you can use). If you are IR (probably 80% of American adults), then you can improve this by eating less often, eating earlier in the day, or eating less carbohydrates (especially those with a high glycemic load) - doing all three is pretty doable and actually tends to work synergistically (endocrinology!). Exercise also helps improve insulin sensitivity, but you can't really outrun a bad diet.
