GLP-1 medications have changed the weight-loss conversation. Drugs such as Zepbound, Wegovy, and Ozempic can dramatically reduce appetite and help people achieve weight-loss results that may have felt out of reach for years.

But there is an important catch: eating less does not automatically mean eating better.

When appetite drops, it becomes easier to consume fewer calories—but also easier to fall short on protein, fluids, fiber, vitamins, minerals, and other nutrients the body needs to remain strong and healthy. And if weight comes off quickly, some of what disappears may be valuable lean mass rather than just body fat.

That was the focus of Financial Experts Network’s recent webinar, “Eat Smart, Not Just Less: Nutrition for GLP-1 Weight Loss,” featuring nationally recognized sports and performance dietitian Leslie Bonci, MPH, RD, CSSD, LDN.

Drawing on decades of experience working with everyone from professional athletes to everyday patients, Bonci offered a practical message for anyone taking a GLP-1: The goal shouldn’t simply be to weigh less. It should be to lose weight while preserving strength, function, muscle, bone, and long-term health.

Why Eating Less Can Create a Nutrition Problem

To understand the challenge, it helps to understand why GLP-1 medications work so well.

Among their effects, these medications decrease appetite and slow gastric emptying. Food remains in the stomach longer, which can help someone feel full sooner and stay full longer. Naturally, that tends to result in eating less throughout the day.

But feeling full isn't the same thing as being adequately nourished.

If someone is eating substantially less food, they may also be consuming less protein, carbohydrate, fat, vitamins, minerals, and fluid. Delayed gastric emptying can also contribute to bloating and constipation, while persistent fullness can make adequate hydration more difficult.

That's why Bonci encouraged people to think differently about their meals. When there is less room for food, every bite has a bigger job to do.

Instead of asking only, “How little can I eat?” a better question may be:

“How much nutrition can I get from the amount I'm actually able to eat?”

Losing Weight Without Losing Too Much Muscle

One of the biggest concerns surrounding rapid weight loss is loss of lean mass.

This is especially relevant as we get older. Bonci explained that age-related muscle loss, or sarcopenia, doesn't suddenly begin in our 60s or 70s. The process can begin much earlier and accelerate later in life.

And muscle isn't just about appearance.

Muscle strength helps us get out of a chair, carry groceries, climb stairs, maintain balance, and remain independent. Losing too much muscle can contribute to weakness, falls, fractures, and diminished function.

For someone already experiencing age-related muscle loss, rapidly losing weight without paying attention to nutrition and exercise can compound the problem.

That makes body composition and function important parts of the weight-loss conversation—not simply the number on the scale.

Protein Matters—but More Isn't Automatically Better

Protein was a major focus of the webinar, but perhaps not in the way people might expect.

Protein is everywhere right now. Grocery-store shelves are filled with protein bars, protein cereals, protein snacks, protein drinks, and products boasting increasingly impressive gram counts.

Bonci's message was more nuanced: Yes, protein is important. But more isn't necessarily better, and not all protein is equal.

Protein supports muscle and bone, but it also plays important roles in immune function, hormones, enzymes, antibodies, blood-glucose regulation, and numerous metabolic processes.

For GLP-1 users, the challenge is finding protein sources that provide substantial nutrition without requiring a large amount of food.

Bonci suggested approximately 0.5 grams of protein per pound of body weight per day as a starting point, with individual needs potentially increasing depending on age, activity, injury, health status, and other circumstances. For adults over roughly age 60, she discussed approximately 0.6 grams per pound as a potential target.

But this isn't a reason to suddenly double your protein intake. Changes should be gradual and individualized.

Think Protein Quality, Not Just Protein Grams

One of the most useful distinctions in the webinar was between protein quantity and protein quality.

The body requires essential amino acids that must come from food. Different protein sources don't necessarily deliver those amino acids in the same quantities or with the same usability.

Animal-source foods such as dairy, eggs, meat, poultry, fish, and seafood generally provide high-quality protein in relatively compact portions. Soy is also a high-quality plant-based option. Other plant foods certainly contribute protein, but larger servings may be necessary to obtain comparable amounts.

That distinction becomes particularly important when someone taking a GLP-1 simply can't eat very much.

For example, Bonci noted that a three-ounce can of tuna can provide approximately 21 grams of protein. Three eggs can provide roughly the same amount. Greek-style yogurt may provide about twice as much protein as regular yogurt for a similar volume.

Compare that with plant foods such as quinoa, bread, broccoli, rice, or peanut butter. They can certainly be part of a nutritious diet, but much larger quantities may be required to obtain similar amounts of protein—and large quantities are precisely what many GLP-1 users struggle to consume.

The takeaway isn't that everyone should eat an animal-based diet. It's that people with limited appetites need to understand what they're getting from the foods they choose.

Don't Let “High Protein” Marketing Fool You

Bonci also encouraged consumers to look beyond the front of the package.

A product claiming 20 or 30 grams of protein isn't automatically a better nutritional choice. What type of protein does it contain? What else comes with it? How well can the body use it? And what is it replacing in the diet?

Collagen is a good example.

Collagen supplements have become enormously popular, but Bonci cautioned against treating collagen as a substitute for a high-quality complete protein. For someone trying to supplement protein intake, she discussed whey protein isolate and soy protein isolate as more useful options.

The same principle applies to milk alternatives.

Dairy milk and soy milk provide high-quality protein. Almond milk, while perfectly acceptable as a beverage for someone who enjoys it, may contain very little protein. Bonci's suggestion was simple: enjoy it if you like it, but don't necessarily count it as a meaningful protein source.

Small Appetite? Make the Food Work Harder

A giant protein shake may sound like an easy solution—until someone taking a GLP-1 drinks it and has no room left for anything else.

Instead, Bonci suggested finding ways to increase the nutritional value of foods without dramatically increasing their volume.

A little unflavored protein isolate might be added to something a person already eats rather than consumed as a large shake. Greek yogurt, cottage cheese, eggs, tuna, milk, fish, and lean meats can deliver meaningful amounts of protein in relatively small portions.

Fiber deserves similar attention.

GLP-1 users need fiber, but abruptly adding huge quantities may worsen GI discomfort. Bonci recommended a gradual approach, particularly for someone already dealing with delayed gastric emptying, bloating, or constipation.

In other words, this isn't a contest to see who can consume the most protein or fiber. Tolerance matters.

The Other Half of Muscle Preservation: Resistance Training

Perhaps the most important point of the entire webinar had nothing to do with food.

If preserving muscle is the goal, eating protein alone isn't enough.

Bonci described resistance training as the primary stimulus for preserving and building lean mass, with protein playing a supporting role. Free weights, resistance bands, machines, and other forms of strength training can all contribute.

Resistance training also benefits bone. When muscles contract against resistance, that action creates a stimulus for the bone as well.

For people losing significant amounts of weight—particularly adults in their 50s, 60s, 70s, and beyond—the combination of adequate nutrition plus resistance exercise may therefore be far more important than simply watching the scale move downward.

A Better Definition of Success

One of the broader lessons from the session is that successful GLP-1 treatment deserves a more thoughtful definition.

Yes, weight loss matters. But so do strength, mobility, hydration, nutritional adequacy, bone health, energy, and the ability to maintain results over time.

Someone who weighs 30 pounds less but has also become substantially weaker hasn't necessarily achieved the outcome they wanted.

The better goal is to use the medication as one part of a larger health strategy—ideally with appropriate medical oversight and individualized nutritional guidance.

As Bonci emphasized throughout the webinar, there is no single eating plan that works for everyone. Age, starting weight, health conditions, activity level, medications, food preferences, GI tolerance, and goals all matter.

GLP-1 medications may make eating less easier. The challenge is learning how to eat smarter with the appetite you have.

5 Questions and Answers About Nutrition and GLP-1 Weight Loss

1. How much protein should someone taking a GLP-1 eat?

There isn't one number that applies to everyone. Bonci suggested about 0.5 grams of protein per pound of body weight per day as a practical starting point, with needs potentially increasing based on age, physical activity, injury, goals, and other factors. For adults over approximately age 60, she discussed around 0.6 grams per pound as a potential target. Importantly, increases should be gradual rather than jumping immediately to a very high-protein diet.

2. What's the best way to preserve muscle while losing weight on a GLP-1?

Protein helps, but resistance training is critical. Bonci emphasized that strength training provides the stimulus needed to preserve or build lean mass, while adequate protein and overall nutrition support that process. Resistance exercise also provides an important stimulus for maintaining bone health.

3. Are protein shakes a good choice for GLP-1 users?

They can be, but a large shake may create too much volume for someone experiencing early fullness. Bonci suggested that protein powder can instead be added in smaller amounts to foods someone already eats. When supplemental protein is appropriate, she discussed whey protein isolate or soy protein isolate as options and recommended looking for independent third-party verification such as NSF, Informed Choice, or USP. 

4. What if increasing fiber makes GLP-1 stomach problems worse?

Fiber is important, but more isn't always better—especially all at once. Because fiber pulls water into the digestive tract, suddenly consuming large amounts may aggravate GI symptoms for some people already experiencing delayed gastric emptying. Bonci's advice was essentially to “make haste slowly” and adjust intake based on individual tolerance.

5. What's the biggest nutrition mistake someone on a GLP-1 can make?

One of the biggest mistakes is focusing exclusively on eating less and losing pounds without paying attention to what is being lost and what the body still needs. Reduced food intake can mean inadequate protein, fluids, vitamins, minerals, and overall nutrition. A more complete strategy considers muscle preservation, strength training, hydration, nutrient quality, GI tolerance, and sustainable eating habits alongside weight loss.

This article is for educational purposes and is not intended to provide individualized medical or nutritional advice. Individuals using or considering GLP-1 medications should consult their physician and other qualified healthcare professionals regarding their individual needs.