Losing weight is hard. Even for the most disciplined among us, sticking to a sustained regimen of nutritious eating , quality sleep , and strength training and aerobic exercise —not to mention managing mental health —is no small feat. Neither is healthy weight loss swiftly attained; the Centers for Disease Control and Prevention (CDC) recommends losing no more than 2 pounds per week for those who plan to keep off what they shed.

Meaning, even if you started your weight loss journey today, you could be months or years away from reaching your goal. So it’s no surprise that weight loss myths and get-thin-quick gimmicks are rampant. Dr.

Nisha Patel , medical director of the Obesity Medicine and Metabolic Health Program within the transplant department at California Pacific Medical Center in San Francisco, recently took to social media to dispel five such falsities that “need to die.” She breaks down each with Fortune . Myth No.

1: Calorie deficit doesn’t matter for weight loss If you’ve ever tried to lose weight through dieting, you know you must create a calorie deficit by burning more than you consume. Easier said than done, especially when that discrepancy is filled by food cravings and hunger pangs. Patel acknowledges these factors contribute to the difficulty of long-term deficit maintenance but says they don’t make it any less critical.

“Calorie deficit is the driver of weight loss, and it still matters what you eat,” says Patel, who is also a certified .