Weight and appetite with age: what the research says about Exercise, GLP-1 drugs, Metformin

What people try

4ExerciseStage 4 · Widely recommended · Free, for almost everyoneExercise is anything that gets your body moving.Main risk: Using weight machines improperly can cause back injury.4GLP-1 drugsStage 4 · Widely recommended · PrescriptionGLP-1 drugs are a class of medicines used to treat type 2 diabetes by lowering blood sugar, and some are used for weight loss in people with obesity.Main risk: The semaglutide page warns that it may raise the risk of thyroid tumors, including a type of thyroid cancer.4MetforminStage 4 · Widely recommended · Prescription, approved for diabetesMetformin belongs to a class of drugs called biguanides.Main risk: Metformin may rarely cause a serious, life-threatening condition called lactic acidosis.3Calorie restriction and fastingStage 3 · Large studies in people · Free; a change in eatingCalorie restriction means eating fewer calories than usual without missing key nutrients, while fasting diets limit when or how much a person eats.Main risk: The NIA says too many ketones in the blood (chemicals made from burning fat) can have harmful health effects.3BerberineStage 3 · Large studies in people · Over-the-counter supplementBerberine is a substance found in several plants, such as goldenseal, barberry, and Oregon grape.Main risk: Berberine has been linked to a harmful buildup of bilirubin in infants, which can cause brain damage.3Testosterone therapyStage 3 · Large studies in people · PrescriptionTestosterone therapy uses man-made testosterone to treat low testosterone, and it can be given as a pill, gel, patch, injection, or implant.Main risk: The page lists several risks of this therapy, including infertility, an enlarged prostate, blood clots, and worsening heart disease.2CreatineStage 2 · Small studies in people · Over-the-counter supplementCreatine is a compound stored in your muscles that supplies them with energy.Main risk: Creatine can cause weight gain because it tends to make the body hold water, but it is otherwise considered safe for healthy adults.

Products

Sorted by the best research stage of each product's ingredients, then by price. The stage describes research on the ingredient, not proof that the product works.

Supplements 14

Recent research

Study in 145 non-frail or pre-frail older adults in a randomized trial

Metformin slowed frailty and lowered biological age in older adults

In a two-year trial, metformin slowed a frailty index score and lowered two blood-based aging clocks compared with placebo.

Summary of earlier studies

Tiny particles and microRNAs may link exercise to brain aging

This review looks at small molecules carried in body fluids that may help exercise affect the aging brain.

Trial in 31 adults aged 50 to 80

Small pilot tests drug and digital tracking for healthy aging in older adults

A small study gave 31 adults in Israel one of two drug mixes for about eight weeks and tracked them with phone-based checks.

New trial

Study compares muscle tiredness in younger and older adults and tests strength training

Researchers plan to compare younger and older adults to learn why leg muscles tire faster with age.

New trial

Can light weight training with blood flow limits help colon cancer survivors with muscle loss?

This is a trial plan that has not reported results yet.

See all the latest research →

What others are writing

Recent articles from health journalists, hospitals and universities. We link to them; we don't write or endorse them.

STAT · May 29, 2026

Healthy weight: appetite and weight