A medical professional holds an apple in their hands.No matter how great the breakthrough in weight-loss technology, it will never upend a fundamental truth: Proper diet and exercise are the most critical tools to achieve healthy weight.

No infomercial, no pill, no injection, no medical procedure can eliminate the path to healthy living. Consumption of good-for-you food and commitment to exercise remain the surest methods for hitting weight-loss goals.

So when a new weight loss drug hits the market—as happened in recent weeks with the appetite-reducing drug Saxenda—health care leaders are quick to remind us that cutting-edge medicine simply cannot erase the need for diet and exercise.

“A comprehensive lifestyle intervention is the most important strategy to achieve and maintain weight loss long-term,” said Nathan Pomeroy, MD, an endocrinologist at Spectrum Health Medical Group. “This may include meeting with a registered dietician and counselor to assist with behavior modification.”

For those who have found little success in dieting and exercise alone, such interventions may ultimately involve prescribed medicine.

“Medications for weight loss, including Saxenda, can be an effective adjunct to lifestyle changes such as reduced-calorie diets and regular physical activity,” Dr. Pomeroy said. “They should be considered in patients who have not been successful with lifestyle change alone, especially those with weight-related medical problems.”

Chronic weight management is an ever-present struggle for millions. About one in three American adults are obese and nearly one in five American youth are obese, according to the Centers for Disease Control and Prevention.

Saxenda is intended for adults who are obese with a body mass index (BMI) of 30 or greater, or those who are overweight (BMI of 27 or greater) who also have at least one weight-related condition such as diabetes, high blood pressure or high cholesterol.

The FDA approved Saxenda a few weeks ago as an option for chronic weight management, paired with lifestyle modification. The manufacturer, Novo Nordisk Inc., expects to have the drug on the market by summer.

Saxenda contains the same active ingredient as the diabetes medication Victoza, but at a higher dose, Dr. Pomeroy said. Novo Nordisk also manufactures Victoza.

The FDA has approved at least four new weight-loss drugs in as many years.

In 2012 the agency approved Belviq and Qsymia, both of which target the brain’s hunger receptors. About four months before green-lighting Saxenda, the FDA approved Contrave, a drug that also controls hunger cravings.

While the three earlier drugs are ingestible, Saxenda is injectable. All four drugs are intended to accompany diet and exercise.

This past week, meanwhile, the FDA approved a first-of-its-kind weight loss treatment device that targets the brain-to-stomach nerve pathway that controls feelings of hunger and fullness. With so many options available, it’s important to depend on a doctor’s guidance.

“Weight loss medications are not an ‘easy answer’ for obesity,” Dr. Pomeroy said, “but they can be an effective component of a comprehensive plan to achieve a healthy weight.”

The drugs are weighted with ample warnings about possible health risks and side effects. The risks of Saxenda include possible thyroid tumors, pancreatitis, gallbladder problems, low blood sugar, increased heart rate and kidney problems.

If you’re looking to hit you ideal weight this year, your best bet is to first sit down with your doctor.

“For patients who are interested in help with weight management, the first step is meeting with your doctor to discuss the issue,” Dr. Pomeroy said. “All patients who would benefit from weight loss should receive counseling on diet, exercise and goals of weight management.”

Medication isn’t the only answer if diet and exercise don’t deliver hoped-for results.