All participants will undergo baseline biopsies of subcutaneous abdominal adipose tissue for cellular/molecular profiling via snRNA-seq and metabolic/physiological assessments (insulin sensitivity, glucose tolerance, and β-cell function). Older obese participants will be randomized into three arms: lifestyle intervention (n=24), senolytics (n=24), or placebo (n=24).

All participants after consent and enrollment will undergo adipose tissue single nuclei RNA sequencing and metabolic phenotyping. Subjects will undergo glucose tolerance testing to document glucose tolerance status. Each subject will be provided an accelerometer to be worn on their dominant wrist for 7 days for assessment of habitual activity.

A dietitian will teach them to utilize the SmartIntake3 smartphone food picture application (app) for a 7-day food record. The app will be used to record amount of each meal consumed in order to determine daily food and beverage and supplement intake and quantity for dietary composition analysis. DEXA analysis will be performed to measure lean and fat body mass.

Subjects will undergo evaluation of physical function/performance, including the Short Physical Performance Battery (SPPB) and VO2 peak testing for assessment of aerobic capacity. The SPPB will be done in older adults only.

The NIH Patient-Reported Outcomes Measurement System (PROMIS) will be used to measure participants' self-report of symptoms, function, and health-related quality of life in the domains of physical, mental and social health.

All subjects will undergo a two-step euglycemic insulin clamp and indirect calorimetry.

Only older obese participants will continue to the randomization to likestyle intervention, senolytic agents or placebo.

Inclusion Criteria:

1. Both Sexes

2. Age: younger lean group 18-30 years with BMI 18.5-24.9 kg/m2; younger obese group 18-30 with BMI 30.0 -39.9; older obese group ≥ 65 years with BMI 30.0-39.9

3. All races and ethnic groups

4. Community dwelling

5. Sedentary (≤1.5 h of exercise per week)

6. Nondiabetic (fasting plasma glucose < 126 mg/dl, 2-h glucose during oral glucose tolerance test (OGTT) < 140mg/dl, and A1c < 6.5%

7. For all female participants who are women of childbearing potential (WOCBP), who are not pregnant or breast feeding, at least one of the following conditions must apply:

   A documented hysterectomy, bilateral salpingectomy, or bilateral oophorectomy Use of a contraceptive method that is highly effective (with a failure rate of <1% per year), preferably with low user dependency (implantable progesterone-only hormone contraception, intrauterine hormone releasing system, bilateral tubal occlusion, vasectomized partner) during the intervention period of the study and for at least 30 days after the last dose of study intervention to eliminate any reproductive safety risk of the study drug.

   Use of a contraceptive method that is highly effective (with a failure rate of <1% per year), with high user dependency, (oral/intravaginal/injectable combined estrogen and progesterone contraception, oral/injectable progesterone only hormone contraception, sexual abstinence) during the intervention period and for at least 30 days after the last dose of study intervention to eliminate any reproductive safety risk of the study drug. In addition to the highly effective methods: male or female condom with or without spermicide; cervical cap, diaphragm, or sponge with spermicide; a combination of male condom with either cervical cap, diaphragm, or sponge with spermicide.

8. ECG value after 10 minutes of resting in the supine position in the following ranges:

120ms<PR<220ms: QRS<120ms; QTc<430ms for males and QTc<450ms for females and normal ECG tracing, unless the investigator considers the ECG abnormality to be not clinically relevant.

Exclusion Criteria:

1. Diabetes, clinically diagnosed or HbA1c > 6.5% and/or fasting plasma glucose > 126 mg/dl and/or use of anti-diabetic medications.

2. Participating in > 1.5 h of structured exercise/week

3. Unstable weight (>3% change in last 3 months)

4. Neurological, musculoskeletal, or other conditions that may limit subject's ability to complete study physical assessment and training

5. Active autoimmune/inflammatory disease including: rheumatoid arthritis, multiple sclerosis, systemic lupus erythematous, inflammatory bowel disease

6. Laboratory parameters outside the normal range:

   • impaired kidney function (eGFR < 30ml/min/1.73m² as calculated by the CKD-EPI equation);
   • impaired liver function (AST or ALT level > 2 times upper limit of normal (ULN);
   • total Bilirubin level > 1.5 times ULN;
   • TSH > 1.5 times ULN or < lower limit of normal (LLN);
   • Hemoglobin <10.0 g/dl; Platelets <125,000 cell/mm³;
   • Platelets < 125,000 cell/mm³
   • Prothrombin time (PT) > 1.0 times ULN
   • Partial prothrombin time (PTT) > 1.0 times ULN.

7. Active gastrointestinal disease; coagulopathy; GI bleed within 6 months

8. Clinically significant heart disease (e.g. NYH Classification >II; ischemia)

9. Peripheral vascular disease (claudication)

10. QTc prolongation >45 msec

11. Use of anti-arrhythmic medications known to cause QTc prolongation, anti-platelet or anti-coagulant medication (see section 5.3)

12. Use of quinolone antibiotics or any other drugs that may prolong the QTc interval (see section 5.3)

13. Pulmonary disease (COPD), severe asthma or exercise-induced asthma

14. Recent systemic or pulmonary embolus

15. Uncontrolled blood pressure (systolic BP>170, diastolic BP>95 mmHg)

16. Smoking, alcohol use (history of regular alcohol consumption exceeding 7 drinks/week for female participants or 14 drinks/week for male participants. 1 drink = 5 ounces [150ml] of wine or 12 ounces [360ml] of beer or 1.5 ounces [45ml] of hard liquor) or recreational drug use (other than marijuana)

17. Pregnant or breastfeeding

18. Postmenopausal women new (within 6 months) to systemic hormone replacement therapy

19. Previous bariatric surgery

20. History of stroke with motor disability

21. Recent (3 years) treated cancer other than basal cell carcinoma

22. Acute or chronic infection

23. Medication that might interfere with metabolic studies (weight loss medication, systemic steroids, immunosuppressants) within 6 months (see section 5.3)

24. Potentially senolytic agents within the last 6 months: fisetin, quercetin, luteolin, dasatinib, piperlongumine, or navitoclax (see section 5.3)

25. History of allergy to dasatinib, quercetin and/or lidocaine.

26. Concurrent enrollment in another interventional trial.

Unidentified data will be shared Research findings will be published in peer-reviewed scientific journals and will be presented at scientific meetings. Data derived from this study will be available upon request to regulatory bodies including NIH, UTHSCSA, DSMB, and the IRB.

Data will become available after study completion and analysis.

Investigators and subjects randomized to study drug/placebo will be blinded to which intervention they receive.