It’s everywhere on the internet—weight-loss testimonials about injectable drugs that claim to combat cravings and deliver dramatic weight loss. Are GLP-1 and GIP receptor agonists the solution to ending obesity worldwide?

Let us first look at how these injectable medications work. There are currently two types marketed under different brand names. One is the GLP-1, or glucagon-like peptide-1 receptor agonist. The other is a combination of GLP-1 and GIP, or gastric inhibitory peptide (also known as glucose-dependent insulinotropic polypeptide) receptor agonist.

GLP-1 and GIP are hormones naturally produced in the gut, specifically in the intestines. These hormones are released when food is consumed. Both hormones, collectively referred to as incretins, stimulate the secretion of insulin from the pancreas’ beta cells to help regulate blood glucose levels and appetite. While these hormones share similar roles as incretins, they also have distinct functions. GLP-1 primarily curbs appetite by slowing digestion and sending signals to the brain that promote a feeling of fullness. On the other hand, GIP regulates appetite through specific brain receptors while promoting fat storage in subcutaneous fat tissue rather than allowing excess fat to accumulate around internal organs, where it poses greater health risks. In addition, GIP promotes bone formation. However, excessive calorie consumption can still lead to weight gain and increased body fat because GIP favors fat deposition. Currently, medications that combine GIP with GLP-1 receptor agonists have demonstrated greater weight-loss outcomes than medications containing only GLP-1.

Unfortunately, the use of these injectable medications is being abused by slimming salons and unqualified practitioners, who sell them to anyone desperate to lose weight, even if they do not meet the medical criteria for treatment. These qualifying conditions include obesity with a BMI of 30 or greater, Type 2 Diabetes Mellitus, prediabetes or insulin resistance, hypertension, dyslipidemia, cardiovascular disease, and obstructive sleep apnea.

GLP-1 and GIP receptor agonists have potential adverse effects. Therefore, they are contraindicated for individuals with a history of or high risk for pancreatitis; certain cancers, particularly thyroid cancer; gastroparesis, a disorder characterized by delayed stomach emptying in the absence of a blockage; inflammatory bowel disease (IBD); eating disorders such as anorexia nervosa and bulimia nervosa; and Type 1 Diabetes Mellitus. Individuals taking birth control pills, antidepressants, antibiotics, or blood thinners should also be aware that these medications may interact with their current treatment.

If you are considering these injectables, consult a licensed physician—not an unqualified practitioner. A thorough medical assessment is necessary to determine whether you qualify for this type of medication. Once the appropriate dose has been established, it is equally important to seek the guidance of a registered nutritionist-dietitian to ensure that you receive optimum nutrition while on treatment.

These medications also have nutrition-related adverse effects. Individuals may experience changes in bowel movements, ranging from diarrhea to constipation, as well as nausea, stomach upset, acid reflux or heartburn, muscle loss, nutrient deficiencies, an increased risk of osteoporosis and osteopenia, and hypoglycemia if they are also taking insulin or oral anti-diabetic medications.

You may be happy because you no longer feel hungry. As a result, skipping meals may become common. However, failing to eat simply because you feel full can lead to nutrient deficiencies and hyperacidity due to an empty stomach.

Bear in mind that these injectable medications are merely tools to help regulate appetite and promote weight loss. You must still establish and maintain healthier lifestyle habits to prevent regaining weight once you discontinue the medication.

While on these medications, aim to eat three small, nutrient-packed meals each day. A predominantly plant-based diet is one of the best ways to nourish your body with phytonutrients and fiber, which help repair damaged cells and reduce inflammation associated with conditions such as diabetes, heart disease, and cancer.

Because these medications promote a feeling of fullness, it is important to limit high-fat foods such as alcoholic beverages; dairy products like butter, cheese, margarine, and whole milk; fried foods; fast food; ultra-processed foods such as canned meats, processed and cured meats, deli products, and packaged snacks; and baked goods such as cookies, pastries, cakes, and bread made from refined flour. Foods high in refined carbohydrates, including pizza and many bakery products, should also be consumed sparingly.

Since muscle loss is common, adequate protein intake is essential. Protein should primarily come from plant sources such as beans, lentils, soy and soy products, nuts, and seeds. Whole grains such as quinoa, adlai, oats, and brown, red, or black rice also provide protein while supplying fiber and carbohydrates that serve as the body's primary source of energy, allowing dietary protein to be used for muscle maintenance and repair. Without adequate carbohydrates, the body will instead use protein for energy, compromising muscle building. Plant-based foods may also help alleviate gastrointestinal side effects. If you choose to consume animal protein, fish is generally considered less pro-inflammatory than red meat such as beef, pork, or lamb.

Make it a habit to eat two to three servings of fresh fruit each day as a snack or dessert. Fruits provide fiber, phytonutrients, antioxidants, vitamins, and minerals that help prevent nutrient deficiencies and support a healthy immune system. Inadequate food intake can compromise immunity, making you more susceptible to illness.

It is important to understand that these medications help curb cravings and reduce overall calorie intake, leading to weight loss. However, you still need to eat for optimum nourishment. You should eat not only because you feel hungry, but because your body needs proper nutrition, even during your weight-loss journey. Consult a registered nutritionist-dietitian to develop a nutrition plan that supports both healthy weight loss and long-term wellbeing.