Yes, it CAN be safe to lose more than two pounds a week as long as you understand some really simple math. And the keyword is “can.”

Certainly, a “starvation” or “crash” approach to dieting is not healthy and can have serious side effects such as fatigue and passing out.

But losing more than two pounds a week does not necessarily require insufficient calories, gimmicks or cutting out entire food groups.

As a former personal trainer, I’ve given the following explanation multiple times to clients about why it can be very safe to lose more than two pounds a week — depending on circumstances.

  • There are 3,500 calories in one pound of fat.
  • Thus, in order to lose one pound of fat, you must create a caloric deficit of 3,500 calories.

This can occur over a week’s time by cutting back 500 calories per day (7 days X 500 = 3,500).

Lose More than Two Pounds a Week Safely

Suppose on the average, you consume 5,000 calories per day. You decide to go on a diet:

  • Controlling your portions
  • Avoiding fast-food fare
  • Saying “No” to gravies, thick sauces and fried foods
  • Cutting back on sugary foods
  • Eliminating sodas and replacing them with water
  • Eating more fruit, vegetables, salads, beans and whole grains.

Your new eating habits come in at about 2,000 calories per day.

Your body has been used to 5,000 calories a day all this time. Now it gets 2,000.

That means each day, there is a calorie deficit of 3,000 calories (5,000 – 2,000 = 3,000).

Multiply this daily deficit of 3,000 calories by seven days (7 days x 3,000) and you get: 21,000 calories.

This means that each week, with your healthy eating habits, you are consuming 21,000 calories LESS than what your body is accustomed to.

Divide 3,500 calories into 21,000, and what do you get? SIX. This means that you’d be losing six pounds a week of fat!

Yet at the same time, you’re getting adequate calories and nutrients.

The weight coming off is not water, contrary to common belief when large amounts of weight are lost. It’s also not muscle.

After all, 2,000 calories/day are enough to feed your body, assuming that your activity levels aren’t off the chart.

When Losing More than Two Pounds a Week Is Not Safe

How much weight you lose per week depends on variables:

  • Resting metabolism
  • Pre-existing body composition
  • Willingness (or not) to gain lean muscle mass through exercise
  • Willingness (or not) to do aerobic exercise
  • General overall daily activity level
  • Presence of medications or a medical condition

“The guideline to lose 0.5-2 pounds per week is a recommendation based on what is most likely a sustainable weight loss rate for most people,” says Amanda A. Kostro Miller, RD, LDN, whose specialties are nutrition counseling, weight loss and medical nutrition therapy.

“However, some research shows that making drastic changes and losing more than two pounds per week can work for some people as well.”

Remember, “drastic” doesn’t necessarily mean a starvation diet or cutting out major food groups.

“The rate of weight loss may also be dependent on what you are losing,” continues Kostro Miller.

“When our weight drops on the scale, we may be losing fat, water weight or even muscle (which can be dangerous).

“Underlying health conditions can cause us to lose more than two pounds per week, so be sure to be followed by a dietitian and doctor.

“Regardless of where your start in your weight loss journey, small changes can be more manageable than bigger changes. However, everyone operates differently.

“If you consume 5,000 calories per day at baseline, dropping to 2,000 calories per day may be way too much of a step for you,” from a psychological standpoint.

“The sweet spot to weight loss is finding a routine that you can do for the rest of your life (because weight management is lifelong) and one that is actually effective.

Depending on where you start, drastically decreasing your calories may be dangerous and/or not recommended.

“According to the Harvard School of Medicine, even if you’re trying to lose weight, women should consume no less than 1,200 calories per day.

“Men should consume no less than 1,500 calories per day. Consuming less than these thresholds may actually deter weight loss.”

Amanda Kostro Miller has worked with U.S. veterans, people with eating disorders and those with various acute and chronic diseases. 
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer.