The side effects of rapid weight loss
Dropping double-digit pounds each week may sound great, but it can actually damage your health.
Most of us have trouble appreciating the journeys in life and just want to fast forward to our destination — and that’s definitely true of weight loss. It’s okay to lose more than two pounds a week at first, since we often “lose water weight loss initially before shifting to fat loss and some muscle mass loss” over time, says Dr. Holly Lofton, M.D., professor of medicine and surgery at NYU Grossman School of Medicine and the director of the Medical Weight Management Program at NYU Langone Health in New York City. Losing more than two pounds a week long-term, though, is considered “rapid weight loss” and can be dangerous. It’s a sign that you’re cutting too many calories from your diet, and it can trigger muscle loss, nutrient deficiencies, and gallstones.
Read on for reasons why going slow and steady is the best way to lose weight on a GLP-1.
4 serious downsides of rapid weight loss
1. You might miss key nutrients
Not eating enough because a GLP-1 has overly diminished your appetite can cause you to miss out on essential vitamins and minerals that your body needs. After several weeks, this could place you at risk for things like electrolyte imbalances, hypoglycemia (low blood sugar), and muscle cramping, says Lofton. A lack of certain micronutrients can also negatively affect your immune system, energy, mood, and even your sleep patterns.
Learn about the ideal diet when you’re on a GLP-1
2. You’ll lose muscle
When you lose weight by restricting calories, your body goes into a catabolic state — in which it effectively gets its energy by breaking down both fat and muscle. This reduces muscle mass as well as muscle quality, causing you to lose strength. A slower approach to weight loss will still result in some muscle loss, but not as much (and that can be minimized even more by upping your protein intake and doing physical activity, especially resistance training).
Learn more about the importance of strength training
3. You probably won’t feel so great
Eating 1,000 calories per day or less can bring on lightheadedness, constipation, headaches, insomnia, and irritability. They result from a combination of low blood sugar and dehydration, since you’re losing so much water weight.
4. Your gallbladder can be affected
“The gallbladder becomes less active during periods of rapid weight loss,” says Lofton. As a result, you’re at a higher risk of getting gallstones, which can cause severe abdominal pain, and even possibly get an inflamed gallbladder. In fact, “there have been reports of patients requiring cholecystectomy, or gallbladder removal surgery, during periods of rapid weight loss,” she says. You might also start losing your hair or notice changes to your menstrual cycle, since your body starts to reserve energy for more important bodily functions.
How to avoid too-rapid weight loss on a GLP-1
Make a habit of strength training regularly and prioritizing foods high in fiber and protein — you can track both with the Weight Watchers GLP-1 Success Program. It’s also key to keep communication open with your healthcare provider and check in on whether or not your weight loss is too rapid. “GLP-1 doses can always be adjusted to slow down weight loss,” says Lofton.
Since normally your dosage increases gradually over the course of several months, it’s easy for your doc to keep you at the same dose, or even slightly lower your dose, in order to curb overly quick weight loss and reduce the risk of possible side effects.