What to Eat on a GLP-1 to Protect Your Muscle and Energy

[00:00:00] Emily Field: Welcome back to Macros Made Easy. I’m your host, Emily Field, registered dietician and strength coach, and a big part of the work I do is helping women lose fat without losing sight of the bigger goal; staying strong, well-fueled, and capable as they age. That’s one of the reasons why I care so much about the conversation around GLP-1 medications.

[00:00:20] Emily Field: These medications can be incredibly helpful for weight loss, but I don’t want the conversation to stop at how much weight someone can lose or how little they can eat. I wanna talk about how we protect muscle, support energy, and make sure the nutrition underneath that weight loss is actually supporting the body you wanna have five, 10, or 20 years from now.

[00:00:40] Emily Field: So in episode 81, we’re talking about what your body actually needs during weight loss, especially if you’re using a GLP-1 medication. One of the interesting things about these medications is that they can make one of the hardest parts of weight loss significantly easier, and that’s eating less. But eating less and eating well are not necessarily the same thing.

[00:01:02] Emily Field: If your appetite is dramatically lower, you may find that you can get through half the day on coffee, eat a few bites for lunch, have a small dinner, and genuinely feel like you don’t need anything else. From a calorie perspective, you might be thinking, “Great, this is working,” but your body still needs protein.

[00:01:18] Emily Field: It still needs vitamins and minerals. It still needs fiber and fluid, and if you wanna continue lifting weights, maintaining muscle, having energy, recovering well, and ultimately feeling good in the body you’re creating, those needs don’t disappear just because your hunger did. So today, I wanna talk about how I think about nutrition when someone has fewer calories and often significantly less appetite to work with.

[00:01:43] Emily Field: We’re gonna talk about protein, fiber, micronutrients, and how to make the food you are eating do more work for you. And if you’re not using a GLP-1, stay with me because, honestly, most of this still applies to anyone pursuing fat loss. The smaller your calorie budget gets, the less room you have for nutritional autopilot.

[00:02:05] Emily Field: Before we get into it, I wanna share a recent Apple Podcast review from aloise85 who wrote, “Really appreciate Emily’s approach. Her information is helpful and clear without hidden diet culture messages.” Thank you so much for that review. I especially appreciate the part about there not being hidden diet culture messages because that’s really relevant to the conversation we’re having today.

[00:02:25] Emily Field: GLP-1 medications have changed the way a lot of people are approaching weight loss, but I think there’s some very old diet culture thinking that can still sneak into the process. We can still fall into the idea that eating less is always better, faster weight loss is always better, and if the scale is moving, then we don’t need to pay attention to what we’re actually eating.

[00:02:45] Emily Field: And that’s not the lens I want us to use here. I’m interested in helping women lose fat, if that’s their goal, while also protecting muscle, supporting their energy, eating enough nutrients, and building a body that stays strong and capable as they age. So today, we’re gonna look beyond simply whether the medication is helping you eat less and talk about what your body still needs while that weight is coming off.

[00:03:08] Emily Field: If you listen regularly and have never left a review, I would love one. It helps other women find the show, and I generally enjoy hearing what you’re thinking and taking away from these conversations. Okay, let’s talk GLP-1s First, I wanna say that less appetite is a tool, it’s not a nutrition plan. And I wanna start here because one of the biggest things I notice when I talk to people using GLP-1 medications is that they can be incredibly effective at reducing appetite and food noise.

[00:03:36] Emily Field: For someone who has spent years feeling like hunger, cravings, or constant thoughts about foods are working against her, that can feel like an enormous relief. Suddenly, eating less doesn’t require the same amount of white-knuckling, planning, or mental energy that it may have required in the past. But there is a pattern I see with clients that I think is really important to talk about.

[00:03:56] Emily Field: When you know the medication is likely going to help you lose weight, it can become very easy to stop paying attention to what you’re eating. You aren’t very hungry, so you grab whatever’s easiest. Maybe that’s a protein bar in the morning, some crackers in the afternoon, a frozen meal at night, a few bites of whatever the kids are eating, and then you realize the next day that you barely ate a fruit or vegetable.

[00:04:18] Emily Field: Or maybe meals start getting replaced with handfuls of snack foods because sitting down to a full plate doesn’t sound appealing anymore. And I wanna be very clear, I’m not saying protein bars, frozen meals, crackers, or other convenience foods are inherently bad. You know me well enough to know that I’m not interested in turning this into a conversation about clean eating.

[00:04:37] Emily Field: Convenience foods can be incredibly useful, especially when your appetite is low. The problem is when convenience becomes the entire strategy simply because weight loss is happening anyway. I’ve had people essentially say some version of, “I know I’m not eating that well right now, but I’m losing weight,” and I understand why that feels reassuring.

[00:04:57] Emily Field: For many people, weight loss has historically been the hardest part. If the scale is finally moving down without you constantly thinking about food, it is very tempting to assume that everything else is taking care of itself, too But weight loss is only telling us that you’re eating less energy than your body is using.

[00:05:15] Emily Field: It doesn’t tell us that you’re getting enough protein. It doesn’t tell us that you’re getting enough fiber. It doesn’t tell us that your diet contains enough vitamins and minerals. It doesn’t tell us whether you’re supporting your strength training, maintaining muscle, staying hydrated, or eating in a way that helps you feel good when the weight comes off.

[00:05:31] Emily Field: And I think this is where GLP-1 medications can create a little bit of a nutritional blind spot. Before the medication, you may have spent a lot of energy trying to control calories because calories felt like the biggest obstacle. Now that appetite is lower and calorie intake kind of takes care of itself more easily, nutrition almost becomes an afterthought.

[00:05:51] Emily Field: But your body still has nutritional requirements, even when your brain isn’t asking for much food. That is the distinction I want you to hear. Your medication can make you less interested in eating, but it can’t look at your day and say, “Hey, you’ve barely had any protein today.” It can’t notice that the only plant food you’ve eaten since Monday was lettuce on a sandwich.

[00:06:12] Emily Field: It can’t recognize that most of what you’ve been able to tolerate lately is beige, packaged, easy-to-grab food, and that overall variety of your diet has gotten really narrow. It can’t decide you probably need something more substantial before your strength workout because you’ve been running on coffee and half a granola bar all day, and it certainly can’t build your meals for you.

[00:06:33] Emily Field: So I think we need to separate two questions. The first is, can I eat less? And for many people using a GLP-1, that becomes dramatically easier. The second is, can I eat less while still giving my body what it needs? That is where the actual nutrition strategy comes in. Whenever calories come down, there is simply less food available to deliver your protein, fiber, vitamins, minerals, essential fats, and carbohydrates.

[00:07:00] Emily Field: If you’re eating quite a bit less than you’re used to, you have fewer opportunities throughout the day to get those things in. That doesn’t mean that every bite needs to be perfectly nutrient-dense, and it doesn’t mean I want you obsessing over whether every food is whole or processed. It means that the foundation of your diet needs a little bit more intention.

[00:07:19] Emily Field: I sometimes think about this as nutrition efficiency. If your appetite is small, I don’t necessarily need you eating a huge volume of food. What I do want is for the foods you can eat to pull a little bit more weight. If you only have room for a smaller breakfast, can we make it one that gives you protein, some carbohydrate, and maybe a fruit rather than just grabbing whatever’s easiest?

[00:07:41] Emily Field: If lunch is gonna be small, can we make sure that there’s actually a meaningful protein source there? If convenience foods are doing a lot of the heavy lifting right now, can we choose convenience foods that are also helping us accomplish something nutritionally? Because once calories get lower and appetite gets smaller, you don’t have as much room for nutritional autopilot The goal is not perfection here.

[00:08:03] Emily Field: The goal is making sure that the medication helping you eat less doesn’t accidentally become the reason you stop thinking about nutrition altogether A lot of women have spent decades being taught that less is better. If 1,600 calories produces weight loss, then surely 1,400 calories must be better. If you’re not hungry for breakfast, great, skip it.

[00:08:24] Emily Field: If you can get through lunch on half a yogurt and a few crackers, even better. And now we have medications that can make eating dramatically less feel surprisingly easy. For someone with a long dieting history, that can reinforce the exact mindset we’ve been talking about a lot on this podcast lately, the idea that success is measured by how efficiently you can make yourself smaller.

[00:08:45] Emily Field: But we just spent an entire episode talking about muscle as your retirement account. The muscle and strength you build and preserve now are part of the physical reserve you get to draw from later. They are what help you carry your suitcase up the stairs, get yourself off the floor, catch yourself when you trip, keep hiking, traveling, gardening, lifting weights, playing with your kids or grandkids, and generally move through life without having to think so hard about whether your body can handle it.

[00:09:11] Emily Field: And in that last episode, we talked about how I would much rather help a woman in midlife lose body fat while preserving muscle than simply help her become 10 pounds lighter at any cost. And that distinction matters enormously here because if the medication makes it possible for you to eat very little and lose weight quickly, the question cannot only be, “How much weight am I losing?”

[00:09:33] Emily Field: I also wanna know, what are we preserving while that weight comes off? Are you maintaining your strength? Are you eating enough protein to support lean tissue? Are you feeling your workouts enough to continue creating a reason for your body to hold on to muscle? Do you have enough energy to train, recover, work, take care of your family, and actually live your life?

[00:09:55] Emily Field: Or are we watching the scale go down while your strength, energy, food quality, and physical capacity go down right along with it? ‘Cause that is not the trade I want you making. And this is why I don’t think the goal of GLP-1 assisted weight loss should be to discover the absolute minimum amount of food that you can tolerate.

[00:10:13] Emily Field: The goal is to create the calorie deficit that supports fat loss while still adequately supporting the body you wanna have when the weight comes off. Those are very different goals. You can absolutely arrive at a lower body weight and also arrive there more depleted. You can lose weight and lose muscle.

[00:10:31] Emily Field: You can weigh less and be weaker. You can see a smaller number on the scale while your workouts are getting worse, your energy is lower, your recovery is poorer, and your diet has narrowed down to coffee, crackers, a protein bar, and six bites of dinner. The scale would still be telling you that the plan is working, but if we zoom out, is it actually the outcome that you wanted?

[00:10:53] Emily Field: This is where I wanna bring back something from that muscle episode. You cannot build or preserve muscle out of nothing. Strength training provides the signal. Your body still needs the resources to respond to that signal Protein matters, total energy matters, carbohydrates matter because it supports the training that gives your body a reason to keep that muscle.

[00:11:14] Emily Field: Sleep and recovery matter. And if your body is in a calorie deficit, especially a substantial one, then preserving muscle becomes something we have to actively support. It’s not something I wanna simply cross my fingers and hope happens when the scale moves down. For women in their 40s, 50s, and beyond, I think this becomes even more important because muscle is increasingly valuable with age.

[00:11:36] Emily Field: We talked about this as a retirement account because I want you thinking beyond the next 10 or 20 pounds. I want you thinking about the body you want five years from now, 10 years from now, 20 years from now. I want the weight loss phase to leave you with a body that is strong enough to do the things you care about.

[00:11:52] Emily Field: I want you to have enough energy for your job, your family, your hobbies, your travel, and the life you’re trying to improve by losing the weight in the first place. And I want you to come out of this process with habits and a body you can maintain five years from now, not just a lower number five weeks from now.

[00:12:08] Emily Field: That is a much more complete definition of successful weight loss. So if your appetite is low and eating less suddenly feels effortless, I don’t want you asking, “How little can I get away with?” I want you asking, “What does the body I’m trying to preserve still require from me?” That question leads us directly to the first nutritional priority, protein.

[00:12:31] Emily Field: You probably knew I was gonna go here first. Protein is important in any fat loss phase because you’re asking your body to operate with less available energy while trying to retain as much lean tissue as possible. And when appetite is low, protein can be surprisingly easy to undereat. This is especially true because some of the foods people best tolerate with a very low appetite are not necessarily high protein foods.

[00:12:56] Emily Field: Toast sounds good, crackers sound good, a little fruit sounds good, soup sounds manageable, maybe a few bites of whatever your family is having. And again, none of those foods are bad. The issue is that you can string together an entire day of very small eating occasions and end up with very little protein.

[00:13:14] Emily Field: So instead of asking what sounds good and then trying to fix the protein problem at eight PM, I would flip the process and ask where is protein in this meal? That doesn’t mean you need to choke down a giant chicken breast when the idea of eating that much food makes you nauseous. This is where smaller volume protein can become incredibly useful.

[00:13:34] Emily Field: Greek yogurt, cottage cheese, eggs, fish, lean meat or poultry in a portion that feels manageable. A smoothie or protein shake, maybe a higher protein soup. There are a lot of ways to get protein that don’t require sitting down to an enormous meal, and you can choose the ones that work for your preferences and tolerance.

[00:13:53] Emily Field: The key is that protein becomes something you plan rather than something you accidentally hope shows up. One thing I often tell clients is to build the meal around the hardest macro first, and when appetite is low, protein is very often the hardest one. If you start there, everything else becomes easier to layer around it But protein is not the only thing your body needs.

[00:14:16] Emily Field: And this is where I want this conversation to go beyond the typical just eat more protein on a GLP-1 advice. Protein matters tremendously, but you’re not a walking set of biceps. We also have to think about whether the overall diet is actually providing enough nutrition. If total food intake drops significantly, micronutrient intake can drop along with it.

[00:14:37] Emily Field: That doesn’t mean that everyone using a GLP-1 suddenly needs a cabinet full of supplements. It means we should pay attention to the diet quality instead of assuming that weight loss proves the nutrition plan is working perfectly. This is where I want to think in terms of nutrient density. What foods give me more nutritional value in a portion I can realistically eat?

[00:14:59] Emily Field: Instead of filling up on foods that offer very little beyond calories, I can include foods that give me protein and calcium, protein and iron, carbohydrate and potassium, fiber and folate, healthy fats and vitamin E. Again, you don’t have to turn eating into a spreadsheet of micronutrients. I don’t expect someone to sit down at dinner and say, “Wonderful, I’m now fulfilling today’s magnesium requirement.”

[00:15:23] Emily Field: I’m just talking about zooming out. Are there fruits and vegetables in your week? Are you eating dairy or other calcium-rich alternatives? Are you eating eggs, seafood, meat, beans, lentils, fortified foods, whole grains, nuts, seeds, or whatever combination makes sense within your preferences? Does the diet have variety?

[00:15:44] Emily Field: Or has your appetite become so low that you rotate through the same three easiest foods every single day? That second situation is where I start paying closer attention. And this is particularly worth discussing with your doctor and dietician if your intake has become extremely limited or if you’re experiencing persistent GI symptoms or if you already had nutrition deficiencies before starting the medication.

[00:16:08] Emily Field: Weight loss and nutritional adequacy are two separate things that we should be monitoring There’s another consequence of eating dramatically less that I don’t think gets talked about enough, and that’s what happens to your vitamin and mineral intake. When food volume goes down, nutrient intake often goes down with it.

[00:16:26] Emily Field: And this matters because many women are not starting from a place of perfect nutritional adequacy to begin with. In fact, current clinical guidance recommends considering micronutrient screening when weight loss is especially rapid or substantial. The ADA specifically calls out nutrients like iron, calcium, magnesium, zinc, and several vitamins as things clinicians may need to pay attention to.

[00:16:50] Emily Field: I don’t say this to scare you or suggest that everyone on a GLP-1 is suddenly deficient on everything. I say it because rapid weight loss can look incredibly successful on the scale while nutrition quality is quietly getting worse underneath it. That’s why I care so much about mineral-rich foods here.

[00:17:08] Emily Field: Calcium, magnesium, potassium, iron, vitamin D, and several other nutrients are already commonly under-consumed. So if your appetite suddenly drops by thirty or forty percent and the foods that still sound good are mostly crackers, bars, toast, frozen meals, and a few bites here and there, you have fewer opportunities to get those nutrients into your day.

[00:17:30] Emily Field: And over time, that can matter. Iron deficiency can contribute to fatigue and reduced exercise tolerance. Inadequate calcium and vitamin D could become particularly important when we’re thinking about bone health. Potassium and magnesium are involved in muscle and nerve function, as well as fluid and electrolyte balance.

[00:17:48] Emily Field: B vitamins play important roles in energy metabolism and neurological function. This doesn’t mean that everyone taking a GLP-1 is gonna develop a vitamin or mineral deficiency, and it doesn’t mean that the medication itself is somehow draining nutrients from your body. The common issue is much simpler.

[00:18:06] Emily Field: If you consistently eat less food, especially less variety, you have fewer chances to consume everything your body needs. And I think this deserves even more attention for women in midlife because we’re already talking about protecting muscle and bone as we age. Weight loss itself can place some pressure on bone.

[00:18:24] Emily Field: We have research showing that calorie restriction-induced weight loss can be accompanied by declines in bone mineral density, which gives me one more reason not to let calcium, vitamin D, protein, and strength training become afterthoughts simply because the scale is moving Can we include dairy or fortified alternatives to give you calcium and protein?

[00:18:44] Emily Field: Can we get potassium from foods like potatoes, fruit, beans, yogurt, and vegetables? Can we include magnesium-rich foods like nuts and seeds, beans, whole grains, and leafy greens? Can we get iron from meat, seafood, beans, lentils, or fortified foods, depending on how you eat? And are you getting enough fluids and electrolytes, especially if you’re dealing with nausea, vomiting, or diarrhea?

[00:19:09] Emily Field: You don’t need to turn your diet into a micronutrient scavenger hunt, and I’m definitely not suggesting that everyone on a GLP-1 needs to start blindly supplementing a long list of minerals. What I am saying is that when you’re eating substantially less, food quality becomes more consequential. If you only have so much appetite to work with, I want as much of that food as possible doing double or triple duty.

[00:19:33] Emily Field: Protein plus calcium, carbohydrate plus potassium and fiber, iron plus protein, magnesium plus healthy fats. That is nutritional efficiency, too. And if your intake has become extremely limited, your weight is dropping very rapidly, you’re experiencing persistent nausea or vomiting, or you already know you have nutrient deficiencies, that is a good reason to have a conversation with your physician or dietician about whether labs or more individualized supplementation makes sense Let’s talk about fiber because constipation is one of the issues I hear about constantly in conversations around GLP-1s, and there are a few things happening here.

[00:20:12] Emily Field: If you’re eating much less food, you’re probably producing less stool simply because there’s less food moving through your digestive tract. Your fiber intake may also have dropped substantially, your fluid intake might have changed, and the medication itself can affect GI motility. So this becomes a perfect little storm.

[00:20:31] Emily Field: The solution, however, is not necessarily to go from barely eating fiber to suddenly pounding giant salads and adding enormous doses of fiber supplements. That may make an already uncomfortable digestive situation even less fun. Instead, I like the idea of gradually increasing fiber-rich foods that are also giving you other nutritional benefits.

[00:20:52] Emily Field: Fruit is a great example, beans and lentils if tolerated, oats, whole grains, vegetables, chia or ground flax. You can work these into foods you’re already able to eat rather than feeling like you now need to complete a daily kale-eating challenge. And this is where fluids matter, too. Fiber and hydration work together.

[00:21:12] Emily Field: If you’re barely drinking and suddenly dramatically increase fiber, that is not necessarily a recipe for GI happiness. So I think about this as another example of why the medication may reduce appetite, but you still need a strategy around eating and drinking. And speaking of strategy, I wanna share one more part of this, how I would actually build a lower appetite day so you’re not trying to cram all of your nutrition into one giant dinner.

[00:21:40] Emily Field: But first, a quick break. Carbohydrates and fats still belong in this conversation, too, and I wanna make this point because whenever we elevate protein, there’s a tendency to accidentally make everything else sound optional, and it isn’t. Carbohydrates are particularly valuable if you’re strength training, walking, running, cycling, or generally trying to remain active while losing weight.

[00:22:02] Emily Field: If your calories are low and your carbohydrate intake is also very low, you might notice that training feels dramatically harder. And fat matters for essential fatty acids, absorption of fat-soluble vitamins, satisfaction of your food, and overall dietary adequacy. Again, I’m not suggesting that there’s one universal macro ratio that everyone using these medications should follow.

[00:22:25] Emily Field: I’m saying this: your eating pattern still needs to function like a diet for a human body. Protein matters, carbohydrate matters, fat matters, fiber matters, micronutrients matter, hydration matters. The medication changed your appetite. It didn’t rewrite human physiology. When someone tells me, “I’ve lost 30 pounds,” obviously that may be exciting, especially if weight loss has felt difficult for years.

[00:22:53] Emily Field: But as a dietician and strength coach, the number itself doesn’t tell me nearly enough about how that process is going. I also wanna know how you feel. Has your energy stayed fairly stable? Are you maintaining your strength and still able to train well? Are you recovering from those workouts? Are you eating enough protein and getting enough overall nutrition to support the body you’re asking to perform for you?

[00:23:16] Emily Field: How’s your digestion? And as your weight comes down, are we doing what we can to make sure that as much of that loss as possible is body fat rather than valuable lean tissue? Because weight loss tells us one thing, your body weighs less. It doesn’t tell us anything about your health, strength, or composition of the body that remains.

[00:23:38] Emily Field: And I think that distinction becomes especially important for women in midlife. We’ve spent the past several episodes talking about how valuable muscle becomes as we age, and I called it your retirement account for a reason. I don’t want you aggressively withdrawing from that account simply because the scale is moving quickly.

[00:23:56] Emily Field: If you’re using a GLP-1 and weight loss is finally happening after years of frustration, I completely understand the temptation to think, “I don’t wanna mess with anything. This is working.” But paying attention to your nutrition is not interfering with the medication or slowing down your success. Eating adequate protein is part of protecting muscle that you wanna keep.

[00:24:16] Emily Field: Strength training gives your body a reason to preserve that muscle. Eating enough total food to have energy, recover, and function well is not failing to take advantage of appetite suppression. Those things are part of the outcome. Because I don’t just want you weighing less at the end of this process. I want you arriving there with as much strength, muscle, energy, and physical capacity as we can reasonably preserve along the way.

[00:24:42] Emily Field: If you’re listening and you’re on a GLP-1, or honestly, if you’re simply in a calorie deficit, I don’t want you walking away feeling like you need to overhaul your entire diet. Instead, look at a very normal day of eating. Not your best day, not the day where you meal prepped and everything went perfectly, just a normal Tuesday.

[00:24:59] Emily Field: Then ask yourself a few questions. First, do my meals have a protein anchor? Can you identify a meaningful protein source at most eating occasions, or are you consistently getting to the end of the day realizing you barely ate any? Second, am I including fiber-rich carbohydrates that actually support me?

[00:25:19] Emily Field: Think fruit, vegetables, oats, potatoes, beans, whole grains, foods that provide energy, fiber, and micronutrients rather than simply filling a small space that you have available. Third, am I building meals that feel good in my body? That may mean keeping fat a little lighter if nausea or fullness is an issue, choosing smaller options, or spreading your food out more evenly instead of trying to eat one large meal at the end of the day.

[00:25:47] Emily Field: And finally, how do I actually feel? Do you have energy? Are you staying strong? Can you train and recover well? How’s your digestion? Are you eating a reasonably varied diet, or have you fallen into the pattern of living on the same handful of easy foods because they’re all you feel like eating? Those questions give us a much more complete picture than simply asking, “Is the scale going down?”

[00:26:10] Emily Field: Because the goal is not only to lose weight, it’s to support the body you wanna have when the weight comes off. GLP-1 medications have changed the weight loss landscape in a major way. For a lot of people, they make eating less much easier, and I think that can be incredibly valuable when the medications are prescribed appropriately and used with proper medical care.

[00:26:31] Emily Field: But easier calorie restriction doesn’t eliminate the need for good nutrition. In some ways, it makes good nutrition even more important. Because you have fewer calories and less appetite to work with, you have fewer opportunities to give your body protein, fiber, micronutrients, carbohydrates, fats, and overall energy that it needs.

[00:26:50] Emily Field: So don’t make your goal, “How little can I eat?” Make the question, “How do I use the appetite I have and the calories I’m eating to build the strongest, healthiest body possible while I lose fat?” That is a very different weight loss strategy. And if you want help answering that question, specifically in the context of GLP-1 medications, that is exactly why I created GLP-1 Strong.

[00:27:14] Emily Field: We’ll go much deeper into the nutrition strategy, muscle preservation, strength training, common side effects, and the habits you need during and after medication-assisted weight loss. You can find the registration information in the show notes. And if you know someone who has started a GLP-1 and is celebrating the number on the scale but hasn’t really thought about what she’s eating or what she wants to preserve along the way, send her this episode because losing weight can absolutely be part of the goal.

[00:27:40] Emily Field: I just want us paying attention to the body we’re building underneath that weight loss, too