⚠️ Medical Disclaimer: This article is for educational purposes only and does not constitute medical advice. Always consult your doctor or healthcare provider before making changes to your medication, exercise, or supplement routine.
Trying to eat right on GLP-1s can feel like solving a puzzle with missing pieces.
Between low appetite and side effects it’s hard to know what actually works—especially when your body feels different than it used to.
That’s why in this special edition of The Weekly Dose, we brought in reinforcements.
Meet Diana Figueroa, a bilingual Registered Dietitian from Doherty Nutrition with deep expertise in diabetes, hormonal health, and—most importantly—helping people like us feel strong, nourished, and in control again.
Diana spent years at Parkland Hospital supporting patients of all ages, from pediatrics to geriatrics. She’s especially skilled at helping folks navigating GLP-1 medications like Mounjaro and Zepbound—where appetite dips, digestion slows, and nutrition can fall through the cracks.
This week, Diana answers your most pressing questions—from collagen and constipation to B vitamins and burnout.
Let’s get into it 👇
Question 1:
We are told to eat protein first. With low appetite, how do we get enough vitamins, minerals, and fibre if we are mostly sated after the protein? Multivitamin? Which one?
Answer from Diana:
With appetite suppression from GLP-1 medications, it's important to be intentional about nutrition. Here are some strategies to help:
1. Choose nutrient-dense foods. Prioritize foods that offer a lot of nutrition in small portions (e.g., leafy greens, avocado, berries, eggs, nuts/seeds, Greek yogurt, legumes). Include a variety of colorful fruits and vegetables across meals/snacks, even in small amounts.
2. Eat small, frequent meals/snacks (5–6+ times per day). Instead of three large meals, aim for snack-sized portions spread throughout the day to reduce fullness and maximize your nutrient intake.
3. Add fiber supplements if needed. Add soluble fiber (like psyllium husk, chia, or inulin) to water or smoothies to support digestion, especially if you're not eating many whole plant foods.
4. Use a high-quality multivitamin. Choose one that’s third-party tested (look for USP, NSF, or ConsumerLab seals).
5. Take advantage of your “hungry days.” Appetite often rebounds mid- to late-week (depending on your injection schedule). Use those days to increase intake of vegetables, fruits, whole grains, and fiber-rich foods.
Question 2:
Are cooked vegetables easier to digest, or should we still try to eat lots of raw veggies for nutritional sake?
Answer from Diana:
Both raw and cooked vegetables offer valuable nutrients, but they impact digestion differently.
1. Cooked vegetables are generally easier to digest. Cooking breaks down the fiber and tough cell walls in vegetables, making them gentler on the digestive system — especially important if you're experiencing GI symptoms like bloating or nausea (common with GLP-1 medications).
2. Raw vegetables offer different benefits. Some vitamins (like vitamin C and certain antioxidants) can be higher in raw veggies, but they also contain more insoluble fiber, which can be harder to tolerate for sensitive stomachs.
3. Balance is best — If you can tolerate raw vegetables without discomfort, including a mix of both raw and cooked is ideal to get a full range of nutrients.
4. Listen to your body. If raw veggies trigger bloating, nausea, or discomfort, it's perfectly fine to stick mostly with cooked versions. You can also try lightly steaming or sautéing veggies as a middle ground.
Question 3:
Any supplements I should take alongside this medication?
Answer from Diana:
Yes because GLP-1 medications can reduce appetite and affect digestion, it's smart to support your nutrition with a few key supplements. Here are the most commonly recommended:
1. Multivitamin (with B12)
– A high-quality multivitamin helps fill nutritional gaps from reduced food intake.
– Make sure it includes vitamin B12, as GLP-1s can sometimes impair B12 absorption over time.
2. Omega-3 Fatty Acids (EPA/DHA)
– Supports heart health, reduces inflammation, and may improve insulin sensitivity.
– Choose a re-esterified triglycerides, this form of fish oil tends to be more bioavailable
3. Electrolytes
– Helps maintain hydration and prevent fatigue or muscle cramps, especially if you’re eating less or losing weight.
– Look for electrolyte powders or drinks with sodium, potassium, and magnesium
Question 4:
Is ingesting collagen powder helpful to the skin's elasticity? (Everyone wants to mitigate the risk of excessive loose skin.)
Answer from Diana:
Collagen powder may offer modest benefits for skin elasticity, but it’s not a miracle solution—especially when it comes to preventing or tightening loose skin after significant weight loss.
What the Research Says:
Several studies suggest that hydrolyzed collagen peptides (the kind found in powders) may improve skin hydration, elasticity, and firmness—especially when taken consistently for 8–12 weeks.
That said, results tend to be modest and individual responses vary. More long-term research is still needed, especially in the context of rapid weight loss.
If You Choose to Take It:
Look for Type I and III collagen peptides from a trusted brand.
For best absorption and results, combine with:
Vitamin C – critical for collagen synthesis
Zinc and Vitamin A – support skin regeneration
Hyaluronic acid – improves skin moisture
Adequate protein intake overall – your body needs amino acids to rebuild tissue
While collagen powder might offer some skin benefits, it won’t prevent loose skin on its own. You’ll get better results by focusing on overall skin and tissue health through:
A high-protein diet
Hydration
Nutrient-rich foods (especially those with vitamin C, zinc, and antioxidants)
Strength training (to support underlying muscle tone)
Question 5:
I’ve heard Mounjaro causes B vitamin deficiencies. True? What is the best solution, if so?
Answer from Diana:
It’s partially true — while Mounjaro (tirzepatide) doesn’t directly cause B vitamin deficiencies, it can increase the risk over time due to reduced appetite, lower food intake, and changes in digestion, especially of key nutrients like vitamin B12. B vitamins are important because they play a critical role in energy, nerve health, metabolism, and red blood cell production. Vitamin B12 in particular may be at risk with GLP-1 medications due to slower gastric emptying and decreased stomach acid (both of which affect absorption).
Best Ways to Prevent B Vitamin Deficiencies:
Eat B-vitamin-rich foods regularly
Focus on animal proteins (beef, chicken, eggs, dairy, fish)
Include leafy greens, legumes, seeds, and fortified grains for plant-based sources
Take a high-quality multivitamin
Choose one that includes the full B-complex, ideally in bioavailable forms (e.g., methylated B12 and folate)
Look for third-party testing (e.g., USP or NSF certified)
Consider a standalone B-complex or B12 supplement if:
You're on a restrictive diet
You’re vegetarian or vegan
Blood work shows a deficiency or borderline levels
Key B Vitamins to Look For in a Supplement:
B1 – Thiamine
B2 – Riboflavin
B3 – Niacin
B5 – Pantothenic Acid
B6 – Pyridoxine
B7 – Biotin
B9 – Folate (preferably as methylfolate)
B12 – Cobalamin (preferably methylcobalamin or hydroxocobalamin)
Question 6:
With slower stomach emptying, is fish oil better absorbed as a liquid off a spoon, or are the soft gels just as good?
Answer from Diana:
Both liquid and soft gel fish oil can be effective, but the form of the oil itself matters more than the format. I recommend a fish oil in the re-esterified triglyceride (rTG) form– This form is more bioavailable and better absorbed than the cheaper ethyl ester (EE) form. It’s also generally easier on the stomach, which is important when digestion is slowed. Make sure to take fish oil with a meal containing fat to improve absorption—especially important on GLP-1s when overall fat intake might be lower.
Question 7:
Is it helpful to take Berberine along with Mounjaro or is that unnecessary?
Answer from Diana:
I don’t recommend it. There is no proven benefits that combining berberine with Mounjaro to be helpful and it can increase the risk of low blood sugar, digestive issues, and nutrient absorption problems.
Question 8:
What is the difference between a semaglutide and tirzepatide?
Answer from Diana:
Semaglutide and tirzepatide are both medications in the GLP-1 family, but they differ in how they work and the hormones they target.
Semaglutide (e.g., Ozempic for type 2 diabetes and Wegovy for weight loss) is a GLP-1 receptor agonist. It mimics the hormone GLP-1 (glucagon-like peptide-1), which helps regulate blood sugar, reduce appetite, and slow stomach emptying.
Tirzepatide (e.g., Mounjaro for type 2 diabetes and Zepbound for weight loss) is a dual GLP-1 and GIP receptor agonist. In addition to mimicking GLP-1, it also activates GIP (glucose-dependent insulinotropic polypeptide), another gut hormone that enhances insulin release and may improve fat metabolism.
Question 9:
Why do greasy foods or sugar packed foods cause GI issues?
Answer from Diana:
Greasy (Fatty) Foods:
Harder to digest: Fatty foods take longer to break down in your stomach and intestines, which can cause them to linger longer in the digestive tract.
This delayed digestion can lead to bloating, nausea, discomfort, and sometimes diarrhea— especially if your digestion is already slowed (like when on GLP-1 medications).
High-fat meals can also stimulate the release of certain digestive hormones that may increase GI symptoms.
Sugar-Packed Foods:
Sugary foods, especially those high in simple sugars or sugar alcohols, can cause an osmotic effect in the intestines.
This means sugars pull water into the gut, which can lead to loose stools, cramping, and gas.
On their own, sugary foods might be less problematic, but they are often consumed alongside greasy foods, which together can amplify GI discomfort.
Question 10:
Should I eat even when I'm not hungry?
Answer from Diana:
Because GLP-1 medications suppress appetite and alter normal hunger signals, it’s important not to rely solely on feeling hungry to decide when to eat. Even if you don’t feel hungry, your body still needs regular fuel and nutrients to function properly.
Here’s why you should eat even if you’re not hungry:
Appetite suppression can mask true energy needs, leading to unintentional under-eating.
Going too long without eating (more than 4 hours) can cause low blood sugar, fatigue, dizziness, or muscle loss.
Regular, balanced meals and snacks help maintain stable energy levels, support metabolism, and prevent nutrient deficiencies.
Question 11:
What do I do when I have nausea after upping a dose?
Answer from Diana:
Nausea is a common side effect when starting or increasing the dose of medications like GLP-1 receptor agonists, but there are several effective ways to help ease your symptoms:
Ginger: Try ginger chews, ginger tea, or fresh ginger—ginger has natural anti-nausea properties.
Peppermint tea: Peppermint can soothe your stomach and help calm nausea.
Cold items: Sucking on ice chips or having cold beverages can be refreshing and reduce queasiness.
Light, bland snacks: Eating small amounts of saltine crackers or plain toast can help settle your stomach.
Eat slowly and in small portions: Avoid large meals, and try eating smaller, more frequent meals throughout the day.
Stay hydrated: Sip water or electrolyte drinks regularly to prevent dehydration.
When to talk to your doctor:
If nausea persists or worsens despite these measures, ask your healthcare provider about medications specifically designed to control nausea.
Never hesitate to reach out if you’re concerned about your symptoms or if they interfere with your ability to eat or stay hydrated.
Question 12:
How to reduce side effects (Nausea, constipation. Etc.)?
Answer from Diana:
Managing Nausea:
Avoid high-fat, greasy meals, especially around the days you increase your medication dose or inject. Large, fatty meals can worsen nausea.
Stick to a consistent, balanced diet that is lower in fat, high in protein, and rich in fruits and vegetables to support digestion and nutrient intake.
Eat small, frequent meals—aim for 5 to 6 meals/snacks every 2–3 hours instead of 1 or 2 large meals. Large meals increase the chance of nausea.
Eat slowly and mindfully to help your stomach adjust.
On injection days, try high-protein, nutrient-packed smoothies that are easy to digest.
Stay well-hydrated throughout the day.
Managing Constipation:
Since eating less can reduce stool volume, it’s important to support regular bowel movements:
Drink plenty of fluids—aim for at least 84 fl oz (about 2.5 liters) per day.
Eat small, frequent meals every 2–4 hours to keep your digestive system active.
Gradually increase fiber intake to about 25–30 grams per day, including both soluble and insoluble fiber.
Incorporate regular exercise to stimulate bowel function.
Consider using digestive enzymes or probiotics to support gut health.
Use gentle over-the-counter remedies if needed:
Magnesium citrate or glycinate (200–400 mg at night) helps draw water into the colon and soften stools.
Psyllium (Metamucil) adds bulk and helps regularity (start with 1 tsp mixed with water once or twice daily).
Prunes or prune juice have natural laxative effects (a few prunes or 4–8 oz juice per day).
Senna tea can be used short-term if backed up but avoid prolonged use.
Additional helpful tools and practices:
Try a Squatty Potty or similar device to improve bowel posture.
Consider pelvic floor therapy if you have difficulty with bowel movements.
Ensure you are eating enough calories to support healthy digestion.
Avoid tight clothing that can restrict your abdomen.
Be mindful of medications that may contribute to constipation.
Manage stress and mental health, as these can impact digestion.
Limit caffeine and high-fat foods that can worsen symptoms.
Question 13:
How does the medication work?
Answer from Diana:
GLP-1 receptor agonists work by mimicking a natural hormone in your body called glucagon-like peptide-1 (GLP-1). This hormone helps regulate blood sugar and appetite through several key actions:
Increase insulin secretion: They stimulate your pancreas to release insulin only when you eat, which helps lower blood sugar levels safely.
Suppress glucagon release: They reduce the release of glucagon, a hormone that raises blood sugar, helping prevent spikes after meals.
Slow gastric emptying: They slow down how quickly food leaves your stomach, which promotes fullness and helps control blood sugar by slowing carbohydrate absorption.
Promote satiety: By acting on brain receptors, they reduce appetite and increase the feeling of fullness, which can help with weight loss.
Question 14:
How do I decide when to come off the medication?
Deciding when to stop your medication is a personalized decision that should be made collaboratively between you, your healthcare provider, and your dietitian. Several factors need to be considered, including:
Your health goals (e.g., blood sugar control, weight loss, overall wellbeing)
How well the medication is working for you
Any side effects or challenges you might be experiencing
Your ability to maintain results through lifestyle changes like diet and exercise
Other medical conditions or medications
Question 15:
I found it difficult to walk, let alone lift weights due to energy levels, what do I do?
Answer from Diana:
Low energy and fatigue can sometimes happen if your calorie intake is too low, especially when appetite is significantly suppressed by medication. Here’s what you can do:
Talk to your doctor: It’s important to discuss your symptoms to rule out any serious side effects or underlying issues. Your doctor can help determine whether adjustments to your medication or treatment plan are needed to protect your health.
Work with a dietitian: A dietitian can help you develop a personalized nutrition plan that ensures you’re getting enough calories and nutrients—even if your appetite is low—to support your energy levels and muscle strength.
Focus on gentle movement: Start with light activities like short walks or stretching, and gradually build up as your energy improves.
Prioritize rest and recovery: Make sure you’re getting enough sleep and managing stress, as both can impact energy levels.
Question 16:
Should I do resistance training if I’m 60+?
Yes! With your doctor’s approval and considering your overall health, resistance training is highly beneficial at any age—even after 60. It helps:
Maintain and build muscle mass, which naturally declines with age
Improve bone density, reducing the risk of osteoporosis and fractures
Boost metabolism and support healthy weight management
Enhance balance, strength, and mobility, helping prevent falls and improve quality of life
Starting with light weights or bodyweight exercises and progressing gradually is key. Working with a trainer or physical therapist can help ensure safety and effectiveness.
Final Bite: A Note of Thanks
Huge thanks to Diana Figueroa and the team at Doherty Nutrition for sharing their expertise with The Weekly Dose family. If today’s answers helped you, let us know! Hit reply, leave a comment, or send us a DM on Instagram (@theweeklydosenewsletter).
And if you’d like to connect with Doherty Nutrition or follow Diana’s work, check them out on social:
📸 Instagram: @dohertynutrition
👍 Facebook: Doherty Nutrition LLC | Dallas, TX
💼 LinkedIn: Doherty Nutrition LLC
If you’re looking for personalized support on your GLP-1 journey—whether it’s nutrition, energy, or making peace with food—Diana and her team are a fantastic place to start.
📆 See you next week! — The Weekly Dose Team
📢 P.S. Want to read past issues? Click here