If you’re using a GLP‑1 medication like semaglutide or tirzepatide, you’ve likely heard a lot about the potential for meaningful weight loss and far less about how to protect your muscle, hair, teeth, and overall nutrition along the way. You’re not alone. Many people are prescribed these powerful medications with minimal guidance on how to eat, supplement, and move their bodies safely while their appetite is dramatically reduced.  So often, it feels so good to finally lose weight that we tend to forget about how the body is adapting and accommodating the reduced amounts of nutrients from eating so much less. 

Large reviews now highlight the real‑world challenges of GLP‑1 therapy: reduced food intake, risk of nutrient shortfalls, loss of muscle and bone, gastrointestinal side effects, and weight regain after stopping the drug if lifestyle foundations aren’t in place (Mozaffarian et al., 2025; Ghusn & Hurtado, 2024). A narrative review of dietary intake on GLP‑1s found calorie reductions of about 16–39%, with very little attention in studies to diet quality, protein adequacy, or micronutrient intake (Christensen et al., 2024).

In other words: these medications change how much you eat, but without support, they don’t necessarily help you eat well.  A behavioral nutritionist, like myself, is trained to bridge exactly that gap.

Why “quick fixes” come with hidden trade‑offs

GLP‑1s are effective tools: clinical trials show average placebo‑corrected weight losses of around 5% with liraglutide, 12% with semaglutide, and 18% with tirzepatide (Ghusn & Hurtado, 2024). But like any strong intervention, they come with unintended consequences if used in isolation:

• Significant calorie cuts can mean inadequate protein and micronutrient intake, contributing to muscle loss and nutritional deficiencies (Christensen et al., 2024).
  • Expert groups now explicitly warn about muscle and bone loss, GI side effects, and nutritional risk when GLP‑1s are used without structured lifestyle and nutrition support (Mozaffarian et al., 2025).
  • When medications are stopped, many people regain a large portion of the lost weight if the underlying behaviors haven’t changed (Mozaffarian et al., 2025).

None of this is a personal failure. It’s a signal that medication alone is only one piece of a very complex puzzle.

How partnering with a behavioral nutritionist changes the trajectory

A behavioral nutritionist can help you use GLP‑1s as a therapeutic window—a time when reduced appetite makes it easier to reshape habits, not starve your body.

Key areas of support typically include:

• Protecting muscle and strength. With lowered appetite, many people under‑eat protein. Evidence suggests that maintaining adequate protein and incorporating resistance training are crucial for preserving muscle and bone during GLP‑1‑induced weight loss (Mozaffarian et al., 2025). A behavioral nutritionist helps you design realistic, tolerable meals and snacks that fit your smaller appetite and your life.
• Preventing nutrient gaps and malnutrition. Because overall intake drops, there’s greater risk of shortfalls in vitamins and minerals such as vitamin D, calcium, and others (Christensen et al., 2024). A nutrition professional can prioritize nutrient‑dense foods you actually like and can tolerate with GLP‑1‑related GI changes, and coordinate with your medical team on appropriate lab monitoring and targeted supplementation when needed.
• Managing side effects compassionately. Nausea, constipation, and other GI symptoms are among the most common reasons people struggle with GLP‑1s (Ghusn & Hurtado, 2024). Rather than pushing through misery, you can work together on gentle meal timing and portion strategies, texture and flavor adjustments, and hydration and fiber plans that respect your body’s signals.
• Addressing the “why” behind eating. Medications can quiet appetite, but they don’t automatically heal emotional eating, long‑standing patterns, or food shame. Behavioral nutrition specifically weaves in tools from psychology, like awareness of triggers, self‑compassion, and alternative coping strategies, so that you’re not relying on the medication alone to keep you on track.
• Planning for after the medication. Expert guidance now emphasizes the importance of structured nutrition and lifestyle therapy to reduce weight regain after stopping GLP‑1s, even though formal trials are still catching up to practice (Mozaffarian et al., 2025). A behavioral nutritionist helps you build sustainable routines while you’re on the medication, gradually transition skills and support if the dose changes or the medication is stopped, and focus on long‑term health markers, energy, strength, labs, quality of life, not just the number on the scale.

You don’t have to navigate this alone

No weight loss “quick fix” is free of trade‑offs. GLP‑1 medications can be powerful tools, but without thoughtful nutrition, movement, and behavior support, they can unintentionally set the stage for muscle loss, nutritional depletion, and disappointment down the line.

Choosing to partner with a behavioral nutritionist is not an admission that you can’t do it yourself. It’s a proactive, evidence‑aligned way to honor your body, protect your health, and make the most of a medication you’ve already chosen. With the right support, GLP‑1 therapy can become less about short‑term shrinking and more about long‑term thriving.