Mandi Knowles, RDN · Senior Director of Research & Development, Wellina
Published: September 1, 2026 · Last reviewed: September 18, 2026
GLP-1 medications like Ozempic®, Wegovy®, and Zepbound® have opened new doors for people struggling to lose weight. If you've started one or are exploring your options, you should know these medications work best when combined with the right nutrition plan, not used as a replacement for one.
Without the right nutrition support, many people experience side effects, low energy, or weight regain.
That's why in May 2025, four of the nation's leading health organizations released expert nutrition guidelines for people taking GLP-1s. Their goal: help you feel better, stay on track, and maintain your results for the long term.
Here's why it matters, what the experts recommend, and simple ways to make it work in your daily life.
How GLP-1s support weight loss and health
GLP-1 medications mimic a hormone your body naturally produces. By binding to receptors in the gut, brain, pancreas, and other organs, they help reduce appetite, curb cravings, slow digestion, and improve blood sugar control. Some people also report better sleep, more stable energy, and reduced inflammation.
Thanks to these effects, GLP-1s can lead to significant weight loss. Clinical trials show people can lose 5 to 18 percent of their body weight in just over a year which is considerably more than what's typically seen with lifestyle changes alone.
But results in everyday life don't always match clinical data. More than half of people stop taking GLP-1s within a year, often due to side effects like nausea, fatigue, and constipation. Others plateau or regain the weight they lost.
These challenges are not just about the medication. In many cases, they reflect what's missing: nutrition support.
How poor nutrition undermines progress
When your appetite drops and side effects kick in, it becomes easy to eat too little. While eating less is part of how GLP-1s work, not eating well enough can interfere with your progress.
Nutrient deficiencies. Low food intake, especially alongside nausea or diarrhea, can cause deficiencies in iron, calcium, magnesium, and B vitamins. These support energy, immunity, and metabolism. When they're lacking, you may notice fatigue, thinning hair, brittle nails, or constipation.
Muscle and bone loss. Whenever you lose weight, you lose both fat and muscle. On GLP-1 medications, lean mass has accounted for roughly a quarter to a third of total weight lost in published trials. This is a similar share to lifestyle-only weight loss, but a larger absolute amount because the total loss is larger. Without enough protein and resistance training, that share can climb. Bone density may also decline, particularly in women and older adults.
Dehydration and electrolyte imbalance. Nausea, vomiting, and diarrhea increase the risk of dehydration. Low fluid intake can lead to fatigue, constipation, kidney strain, and irregular heartbeats.
Weight regain. GLP-1s reduce hunger but don't build lasting habits. Without a plan for balanced eating, many people regain weight, about two-thirds of what was lost, within a year of stopping, in one large study.
These concerns are why experts emphasize that GLP-1s are a tool, not the entire solution.
What the experts recommend, and how to make it work
The American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society released joint nutrition guidelines in 2025, the first collaborative guidance of its kind.
Their recommendations are based on research showing that people who combine GLP-1 treatment with nutritional support lose more weight, experience fewer side effects, and are more likely to maintain their progress after stopping medication.
1. Prioritize protein
Why it matters: Protein helps preserve muscle mass and bone strength while you lose weight. It also helps keep you full and satisfied.
How to do it:
- Aim for roughly 1.2 to 1.6 grams of protein per kilogram of body weight per day, spread evenly across your meals. For many adults that works out to about 80 to 120 grams daily.
- Pair it with strength training two to three times a week. Protein alone doesn't protect muscle; the combination does.
- Include a protein source at every meal and snack, and eat the protein first. With a smaller appetite, you want it in before you feel full.
- Choose lean options like eggs, chicken, fish, dairy, tofu, and beans over red or processed meats. Greek yogurt, cottage cheese, and egg whites give you a lot of protein in a small portion.
- Use protein shakes or bars if needed. Look for options low sugar and at least 10 grams of protein per serving.
2. Make every bite count
Why it matters: With reduced appetite, every bite should provide vitamins, minerals, and fiber.
How to do it:
- Use the plate method: half non-starchy vegetables like leafy greens, peppers, or zucchini, then split the rest between lean protein and fiber-rich grains.
- Choose whole grains over refined ones more often.
- Review your diet with a healthcare provider to decide whether supplements are needed.
3. Avoid foods that make side effects worse
Why it matters: High-fat and ultra-processed foods can trigger or worsen nausea and digestive symptoms and they crowd out foods carrying the nutrients you need.
How to do it:
- Skip fried foods and processed meats. Choose baked, roasted, or broiled proteins instead.
- Cut back on sugary drinks and snacks.
- When nausea hits, reach for gentle options: bananas, oatmeal, broth, plain crackers.
4. Eat small, frequent meals
Why it matters: Smaller meals spread through the day help you meet your nutrition goals even when your appetite is low.
How to do it:
- Aim to eat every three to four hours, even if it's just a snack.
- Keep easy combinations on hand: a protein shake with fruit, cottage cheese and berries, apple with peanut butter, half a sandwich with veggie sticks, tuna on whole grain crackers.
- Use phone reminders if hunger cues aren't prompting you.
5. Stay hydrated
Why it matters: Nausea, vomiting, diarrhea, and blunted thirst cues all raise your dehydration risk which then worsens constipation, drains energy, and strains your kidneys and heart.
How to do it:
- Keep water or herbal tea with you through the day.
- Sip between meals rather than during them, so you don't fill up before you've eaten.
- Try ginger tea, broth, or an electrolyte drink if nausea is an issue.
6. Build cooking confidence over time
Why it matters: Cooking skills support long-term success by giving you more control over what you eat.
How to do it:
- Cook one more meal at home each week than you did last week.
- Lean on simple formats: sheet pan dinners, one-pot soups.
- Prepared meals can help you practice a balanced eating structure while you build the skills to cook more on your own.
What a day might look like
A practical example for someone aiming at roughly 100 grams of protein with a reduced appetite:
- Breakfast — Greek yogurt with berries and a spoonful of nut butter (around 20g protein)
- Mid-morning — a protein shake, sipped slowly (20g)
- Lunch — half a turkey sandwich on whole grain with a side salad (20g)
- Afternoon — cottage cheese with sliced apple (15g)
- Dinner — grilled chicken or fish, a grain, and vegetables (30g)
Five small occasions rather than three large ones. If a full meal feels like too much, that's the point, the structure is designed around a smaller appetite rather than fighting it.
What about keto or intermittent fasting?
Some people pair GLP-1s with keto or intermittent fasting. These approaches may work for some, but both can cause complications during treatment.
Keto is very low in carbohydrates. Since GLP-1s lower blood sugar, the combination can push levels dangerously low. The high-fat focus may also worsen nausea and reduce fiber intake.
Intermittent fasting builds in long stretches without food. Combined with an already-reduced appetite, that makes it harder to meet your nutrition needs and raises the risk of blood sugar drops. If you're curious about fasting more broadly, our look at what the research actually shows covers where it helps and where it doesn't.
Instead, focus on balanced meals you can stick with. A steady routine that fits your life will do more for your results than any schedule.
Frequently asked questions
How much protein should I eat on a GLP-1?
Roughly 1.2 to 1.6 grams per kilogram of body weight per day, spread across your meals, about 80 to 120 grams for many adults. Pair it with resistance training two to three times a week to protect muscle.
Will I lose muscle on a GLP-1?
Some muscle loss happens with any weight loss. In published trials, lean mass has made up roughly a quarter to a third of total weight lost on these medications. Adequate protein and regular strength training are what reduce that share.
What should I eat when a GLP-1 makes me nauseous?
Gentle, low-fat foods: bananas, oatmeal, plain crackers, broth, ginger tea. Eat smaller amounts more often, sip fluids between meals rather than with them, and avoid fried or heavily processed foods, which tend to make nausea worse.
Can I do intermittent fasting while taking a GLP-1?
It isn't recommended. GLP-1s already suppress appetite, and adding long fasting windows makes it harder to meet your nutrition needs while raising the risk of blood sugar dropping too low.
What happens if I stop taking a GLP-1?
Weight regain is common. In one large study, participants regained about two-thirds of the weight they'd lost within a year of stopping. The eating habits you build while on the medication are what carry results forward.
Do I need supplements on a GLP-1?
Possibly, but not automatically. Low food intake can lead to shortfalls in iron, calcium, magnesium, and B vitamins. Review your intake with a healthcare provider rather than supplementing on guesswork.
The bottom line
GLP-1 medications can be a powerful tool, but nutrition is still the foundation. The right plan reduces side effects, protects your energy and muscle, and makes your results last beyond the medication itself.
Healthy weight loss isn't just about eating less. It's about making sure that what you do eat is doing enough.
About the author
Mandi Knowles is a Registered Dietitian Nutritionist and Senior Director of Research & Development at Nutrisystem, where she leads nutrition standards for Wellina.
This article is for general information and is not medical advice. Talk to your doctor or a registered dietitian before starting, stopping, or changing any medication, or before making significant changes to how you eat.
References
Expert Panel. Nutritional priorities to support GLP-1 therapy for obesity. Obesity. Published May 30, 2025. doi:10.1002/oby.24336
Wilding JPH, Batterham RL, Davies M, et al. Weight regain and cardiometabolic effects after withdrawal of semaglutide: The STEP 1 trial extension. Diabetes Obes Metab. 2022;24(8):1553–1564. doi:10.1111/dom.14725
*Ozempic® and Wegovy® are trademarks of Novo Nordisk A/S. Zepbound® is a trademark of Eli Lilly and Company. Neither company is affiliated with Wellina®.
