For everyone else, read on.

Eating Well on GLP-1s: What Actually Changes, and How to Cover the Gaps

The short answer

GLP-1 medications work by reducing appetite and slowing digestion, and research shows they typically cut daily calorie intake by somewhere between 16 and 39 percent. That's the intended effect for weight management, but it has a side effect that gets far less attention: less food also means less room to get protein, iron, calcium, vitamin D and B vitamins from diet alone.

If the diet before starting a GLP-1 wasn't especially nutrient-dense, eating less of it isn't automatically a healthier outcome, it's the same gaps, at a smaller volume. This guide covers what the research actually says about those gaps, what's worth prioritising day to day, when it's worth involving a GP or dietitian, and where simple supplementation can genuinely help.

What GLP-1s actually do to eating

GLP-1 medications work by mimicking a hormone involved in appetite regulation and digestion, reducing hunger, extending fullness, and slowing how quickly food leaves the stomach. That combination is what makes them effective for weight loss, and it's also what makes eating well while using them a genuinely different exercise than eating well normally.

Research on real-world use has found daily protein intake among GLP-1 users can fall well below standard recommendations, with some studies finding the majority of users under-consuming protein relative to national guidance. Deficiencies in vitamin D, iron, calcium and B vitamins, particularly B12 and thiamine, have also been documented within the first year of use in multiple studies.

Why eating less doesn't mean needing less

It's a natural assumption that if the goal is weight loss, eating less is simply working as intended, and in one sense it is. What doesn't shrink alongside food intake is the body's underlying need for protein, to maintain muscle, and for the vitamins and minerals involved in energy, bone health, and red blood cell production.

This matters most for people who were already getting a fairly average or below-average diet before starting a GLP-1. A smaller volume of the same eating pattern tends to concentrate the same gaps, rather than resolve them, and several clinical reviews have specifically called for nutritional care to be built into GLP-1 treatment rather than left to patients to work out alone.

What the research flags as nutrients of concern

A recurring set of nutrients comes up across the research on GLP-1 use, worth prioritising specifically rather than assuming a generally healthy diet automatically covers them at a reduced volume.

• Protein — for maintaining muscle mass during weight loss
• Vitamin D — commonly under-consumed, and one of the most frequently documented deficiencies in GLP-1 users
• Iron — particularly relevant given reduced overall food volume
• Calcium — relevant to bone health, especially alongside reduced food intake
• B vitamins, particularly B12 and thiamine — involved in energy metabolism

None of this means every GLP-1 user has these deficiencies. It means these are the specific areas worth paying attention to, rather than assuming a smaller version of a normal diet covers everything it used to.

Protein: what the guidance says, and the caveat that matters

Clinical guidance for people on GLP-1s generally points to a higher protein target than the general adult recommendation, commonly cited in the range of 1.2 to 1.6g per kilogram of body weight daily, aimed at protecting muscle mass during weight loss.

That range comes with an important caveat: it's generally lower for people with chronic kidney disease, which is relevant given how many GLP-1 users come from a type 2 diabetes population where kidney involvement is common. This isn't a number to self-apply without context. A GP or dietitian who knows your actual health picture is the right person to set a specific target, this guide is describing what the general guidance says, not prescribing an individual number.

What to actually prioritise day to day

General clinical guidance for eating well on a GLP-1 tends to emphasise a few consistent principles, worth treating as orientation rather than a rigid plan.

• Protein at most eating occasions, from complete sources where possible
• Nutrient-dense whole foods over highly processed options, since every eating opportunity now carries more nutritional weight than before
• Smaller, more frequent portions where large meals feel uncomfortable, a common effect of slowed digestion
• Adequate fluid and fibre, since fibre intake commonly drops alongside reduced food volume, which can affect digestion

None of this is about eating more than feels comfortable. It's about making the eating that does happen count for more, which is a different goal from the general "eat less" instruction GLP-1s are often summarised as.

When to involve a GP or dietitian

Several clinical reviews have specifically called for registered dietitian involvement in GLP-1 care, including baseline nutritional assessment and ongoing monitoring, because integrated nutrition support is currently the exception rather than the norm in real-world prescribing. If any of the following apply, it's worth raising with whoever is managing your prescription rather than addressing through diet or supplementation alone:

• Persistent fatigue, dizziness, or hair loss beyond what feels like normal adjustment
• Noticeable loss of strength or muscle, not just weight
• Ongoing digestive discomfort that doesn't settle with smaller portions
• Any existing kidney, liver, or other condition that affects dietary requirements

This guide is general information, not an individual nutrition plan, and it isn't a substitute for that conversation.

Where supplementation can genuinely help

Supplementation isn't a fix for a poor diet, and it isn't a substitute for the professional monitoring described above. What it can reasonably do is make it easier to consistently cover the nutrients most commonly affected, protein and the vitamins and minerals named earlier, on days when appetite or portion size makes that harder to do from food alone.

TOTEMIC's Foundation blocks, PROTEIN, CORE and optional CARB block, are built around exactly that kind of coverage: a full protein serving and 26 vitamins and minerals, 25 of them at 100% NRV, in one daily sachet. That's a structural claim, not an efficacy one. TOTEMIC isn't saying this addresses GLP-1 side effects specifically, or compensates for how the medication works, only that it's a straightforward way to help hit daily protein and micronutrient intake without juggling several separate products, which matters more when appetite and portion tolerance are already reduced.

Optional goal blocks are also available if a specific priority applies, gut comfort, joint support, cognitive load, or general strength work, each listing exactly what's in it. None of them are positioned as addressing a GLP-1 side effect directly, for the same reason nothing else on this site makes that kind of claim: it isn't one TOTEMIC is able to stand behind.

FORM

Creatine monohydrate, HMB, L-arginine, L-alanine. Creatine increases physical performance in successive bursts of short-term, high intensity exercise, at a daily intake of 3g, which FORM's dose meets.

BOND

Bovine collagen, glucosamine, chondroitin, MSM, vitamin C. Contains bovine and avian derived ingredients.

BIOME

Chicory root inulin, with live cultures of Lactobacillus acidophilus and Bifidobacterium bifidum.

CLARITY

L-tyrosine, acetyl L-carnitine, lion's mane extract, coenzyme Q10, vitamin B5, huperzine A.

What TOTEMIC doesn't claim

TOTEMIC doesn't claim to interact with, enhance, or offset the effects of any GLP-1 medication. It isn't a medical product and isn't positioned as part of drug therapy. The claim is limited to what's checkable: a full protein serving and a complete range of vitamins and minerals, in one daily sachet, for people who want an easier way to cover the basics when appetite is reduced. Anything beyond that, whether supplementation is the right approach for a specific person, what dose of anything is appropriate, whether a deficiency is already present, is a conversation for a GP or dietitian, not a blog article.

Frequently asked questions

How do I make sure I'm eating right on GLP-1s?

Prioritise protein at most eating occasions, choose nutrient-dense whole foods over processed ones, and don't assume a smaller version of a previous diet automatically covers the same nutritional ground. If portions are hard to tolerate, smaller and more frequent meals tend to help. For an individual target, particularly around protein, a GP or dietitian is the right person to ask.

What supplements should I take with GLP-1s?

Research points to protein, vitamin D, iron, calcium and B vitamins as the areas most commonly affected. Whether supplementation is needed, and at what level, depends on individual diet and any existing health conditions, which is worth discussing with whoever manages your prescription. A structured daily option like TOTEMIC's Foundation blocks can make it easier to consistently cover protein and micronutrients without assembling several separate products, if that's a genuine gap for you.

Do GLP-1s cause nutrient deficiencies in everyone who takes them?

No. The research shows deficiencies are common, not universal, and risk depends heavily on diet quality before and during treatment, dose, and individual factors. It's a real and under-discussed risk worth being aware of, not an inevitability.

Is 1.2 to 1.6g/kg of protein right for me specifically?

That's the range generally cited in clinical guidance for GLP-1 users, but it's lower for people with kidney disease, and individual circumstances vary. It's worth confirming an actual target with a GP or dietitian rather than applying a general figure directly.

Can TOTEMIC replace dietitian support while I'm on a GLP-1?

No. TOTEMIC is a way to help cover daily protein and micronutrient basics, not a substitute for individualised nutritional assessment or monitoring, which several clinical reviews specifically recommend as part of GLP-1 care.

The short version

GLP-1 medications reduce how much people eat, not how much nutrition they need. Protein, vitamin D, iron, calcium and B vitamins are the areas most consistently flagged as at risk in the research, and a smaller version of a previously average diet tends to concentrate those gaps rather than close them. Nutrient-dense food and adequate protein come first. Where that's genuinely hard to hit consistently, a simple daily option that covers the basics can help, without claiming to be more than that.

Hopefully that was all useful for you on your new journey. If TOTEMIC seems like an easy solution for you, click the button below and build your mix in 8 clicks.