When taking a GLP-1, it is extremely important to prioritize nutrient dense foods to prevent undereating. It can lead to deficiencies and dysfunction. This is why it’s important to know your caloric requirements while on GLP-1s.
What are GLP-1s
Glucagon-like peptide-1 (GLP-1) is an incretin hormone naturally produced in the body. It helps to regulate blood sugar levels by stimulating the pancreas to release insulin and slowing down stomach emptying.
GLP-1 receptor agonists (GLP-1 RAs) are a class of medications that are used to support the treatment of metabolic conditions, including type 2 diabetes and obesity. Research has supported its use in treating cardiovascular disease, one of the leading causes of mortality and morbidity worldwide, reducing risks of heart attack and strokes in those with type 2 diabetes. GLP-1s may slow the progression of chronic kidney disease (CKD) by addressing two risk factors: type 2 diabetes and obesity. Metabolic syndrome, comprised of 3 out of 5 markers including elevated blood pressure, blood sugar, cholesterol, waist circumference and low HDL, improves through the use of GLP-1s.
In 2022, the International Journal of Molecular Science published a systematic review by Laurindo, et al. demonstrating the benefits of GLP-1 beyond the tradition use of type 2 diabetes and obesity. The hormone, they say, affects other organs and cells, like the liver, pancreas, brain, heart, GI tract, and fat cells. As such, GLP-1 analogs benefit other conditions such as Alzheimer’s Disease, Parkinson’s Disease, depression, chemical dependency, and non-alcoholic fatty liver disease (NAFLD). The only cause for concern is the adverse gastrointestinal effects that tend to arise while on the medication.
What are common GLP-1 medications?
Common GLP-1 medications include:
Semaglutides: a medication that is used to treat type 2 diabetes, obesity, and reduce the risks of cardiovascular events.
- Ozempic: an injection approved for adults with type 2 diabetes. It helps to improve blood sugar and lower risks of cardiovascular events (heart attack and stroke).
- Wegovy: an injection approved for chronic weight management in adults and adolescents (12+) with obesity or one weight-related medical condition. This includes reducing risks of cardiovascular events in those with diagnosed cardiovascular disease.
- Rybelsus: Is an oral tablet used for blood sugar control in adults with type 2 diabetes.
Dulaglutide: a GLP-1 receptor agonist that mimics the natural hormone to increase insulin release as needed. It also decreases glucagon and slows stomach emptying. Dulaglutide has a boxed warning due to its potential thyroid C-cell tumors based on animal studies. Those with a history of multiple endocrine neoplasia syndrome type 2 or medullary thyroid carcinoma should avoid this.
- Trulicity: an injectable approved for adults and children (10+) with type 2 diabetes. It’s also for adults with type 2 diabetes with a cardiovascular disease diagnosis or multiple risk factors to reduce risks of major cardiovascular events.
Exenatide: an injection used to treat type 2 diabetes in conjunction with diet and exercise.
- Byetta: Is an injection used in adults with type 2 diabetes to help control blood sugar levels.
- Bydureon: This has been discontinued. This had a boxed warning from the FDA regarding potential risks of thyroid C-cell tumors based on animal studies.
Understanding the Purpose of GLP-1s
The purpose of GLP-1s is to stimulate insulin release from the pancreas when consuming foods; specifically, glucose. In doing so, it suppresses glucagon, the hormone responsible for raising blood sugar levels. GLP-1s slow down the rate in which food leaves the stomach, supporting lower blood sugar levels. They aid in weight management by increasing the sensation of being full, signaling to the brain additional food isn’t necessary.
There are consequences associated with slow gastric emptying and reduced food intake. For example, nausea, vomiting, abdominal pain, and bloating. However, another major consequence is malnourishment.
Why Nutrition Matters
While one of the most appreciated benefits of GLP-1s is the weight loss, it can come at a hefty price! The British Medical Journal (2025), one of the oldest and respected peer reviewed medical journal, published Malnutrition with use of GLP-1 agonists is an underestimated real world harm. The condition of malnutrition risk is often overlooked because of the assumption that obese persons overconsume, when it could result from a lack of access to nutrient dense food. “One trial of tirzepatide27 suggested appetite suppression through drug use can also result in long term consumption of only 800 calories/day. Current guidelines have not highlighted the risks of malnutrition with this degree of caloric restriction nor stipulated the need for meal replacement when users consume <800 calories/day.” No studies have been conducted that assess diet quality, nutritional status, and/or risk of malnutrition.
Obesity exacerbates the risk of malnutrition through inflammation in the GI tract and an imbalanced gut microbiome, which impacts the gut’s role in absorbing vitamins and minerals. Medications prescribed for comorbidities deplete and impair nutrient absorption, including magnesium, thiamin, B vitamins, as well as severely low glucose levels, metabolic acidosis resulting from anorexia, and other nutritional adverse effects.
Know Your Caloric Requirements
This is why it is so important to know your caloric requirements while taking GLP-1s. Focusing on what and how much you eat means tracking, and this is important for a few reasons. When you focus on the right foods, the less you experience common side effects, such as constipation and nausea. The less you consume because of the GLP-1, the more nutrient dense foods you need to prevent malnutrition.
Your calorie requirements are going to depend on your age, height, weight, basal metabolic rate, and activity levels. Those on GLP-1s, who reduced their caloric intake 16-39%, had reductions in energy intake and reductions in appetite. However, Mozaffarian, et al., (2025) caution that such drastic reductions may lead to inadequate intakes of essential vitamins and minerals, especially for women consuming less than 1,200 calories per day and less than 1,800 calories for men.
What You Should Focus On
Nutrient dense foods include adequate protein, fiber, and hydration. Protein requirements are 1.2-1.5 g/kg of body weight. For example, a person weighing 150 pounds (68 kg) would require a protein intake range of 82-102 grams daily. Protein intake preserves lean muscle mass, increases satiety, improve metabolism, and stabilizes blood sugar.
To prevent against constipation, increase satiety, and support blood sugar levels, fiber intake should range between 25-35 grams per day.
Drinking half your body weight in ounces not only helps overall body functions, but prevents against constipation, dehydration, and side effects like nausea and fatigue.
Participate in strength training and movement. Completing at least 150 minutes of moderate intensity aerobic activity and 2-3 sessions of strength training per week helps to preserve lean muscle mass, improve bone density, and support metabolism.
Are you considering GLP-1s or in need of support while taking them? Schedule a session with me! Let’s best determine where your caloric intake should be, and how to create a nutrient dense meal plan to best support your goals.