With the rise in popularity of newer weight loss medications, a lot of people are curious about how these drugs interact with different diet plans. I’ve been asked a few times about the effects of intermittent fasting on GLP-1 medications so I’ve decided to dedicate an entire article about this.
Combining intermittent fasting with GLP-1 medications might offer some benefits but it would be prudent to ask your healthcare provider first if you really should do them at the same time. According to the International Food Information Council, based on a 2023 survey, it’s been found that intermittent fasting has become one of the most popular methods people have used in order to lose weight (12%).
People who have struggled with weight loss may have found success with diets like intermittent fasting or the keto diet. But if you’re wondering if it’s safe to fast while taking GLP-1 drugs, this post has the answer you’re looking for.
What is Intermittent Fasting?
Intermittent fasting is not essentially a diet but an eating pattern that alternates between periods of fasting and eating. The focus is on when to eat rather than what to eat.
Fasting and eating durations vary. Popular variations of intermittent fasting include the 12:12 (12 hours of fasting with a 12-hour eating window) and 16:8 (16 hours of fasting with an eight-hour eating window). Some also follow the 5:2 method (five days of normal eating and 2 days of restricted eating).
No matter how you structure your fasting, the benefits can quickly add up. In one study published on the National Library of Medicine which looked at 27 intermittent fasting trials, it was determined that participants lost anywhere between 0.8% to 13% of their baseline weight. Intermittent fasting not only reduces calorie intake but also enhances fat burning, specifically abdominal fat.
Studies indicate that intermittent fasting can also improve insulin sensitivity and lower insulin levels. Moreover, research suggests that it triggers autophagy, a cellular repair process that eliminates dysfunctional components which in turn protects against diseases.
How Does Intermittent Fasting Interact with GLP-1 Levels?
GLP-1 medications mimic the natural hormone GLP-1, which slows gastric emptying and promotes a feeling of fullness (satiety). Intermittent fasting can increase GLP-1 secretion during fasting periods so that you can reap significant benefits.
Is Fasting While on GLP-1 Safe?
Intermittent fasting enhances weight loss when combined with GLP-1 medications and at the same time it also releases growth hormones to protect your body against muscle waste associated with GLP-1.
However, intermittent fasting with GLP-1 medications is not safe for everyone. People with diabetes should monitor their blood glucose closely and if you have a history of hypoglycemia, you need to know that fasting can increase the risk of low blood sugar.
Pregnant or breastfeeding individuals should avoid GLP-1 medications as their safety is not well known and fasting can lead to nutrient strategies and deficiencies. Certain conditions like severe renal impairment or gastroparesis can increase adverse reactions when combining GLP-1 medications with fasting. Older people (seniors) and frail individuals may also be more susceptible to side effects like vomiting, nausea or dehydration.
If you’re already practicing intermittent fasting and are thinking of taking GLP-1 RAs, consider the type of fasting you are doing. A 12:12 method might not pose issues unless you have glucose management problems, but for prolonged fasting, consider switching to the 12:12 method instead.
Finally, regardless of your fasting method or health history, always consult your healthcare provider before making dietary changes while on GLP-1 medication. This will help determine if you’re a candidate for this combination and establish the best timing for taking GLP-1 when fasting.