Given all the benefits of plant-based eating—from reduced risk of heart disease to lower greenhouse gas emissions—it’s not hard to see why so many people are gravitating toward a veg-forward lifestyle these days. According to 2021 survey data from the International Food Information Council, five percent of American adults now follow a plant-based diet—and you very well might be one of them! 

Still, if you’ve noticed some not-great changes to your health since leaving animal products behind (or even if you just struggle to maintain the willpower to resist the siren song of the occasional steak), it’s possible that a fully plant-based diet isn’t the best fit. That’s no disrespect to vegetarian eating habits! The simple truth is that not every eating plan works for every person—and there’s no shame in deciding that plant-based isn’t the right path for you.

Here are six signs your plant-based diet isn’t working out, plus how you might tweak your approach if sticking with an all-veg lifestyle is important to you.

1. You’re Feeling Fatigued

A burst of renewed energy after eliminating animal products can happen for some people…but not for everyone. In fact, you might find switching to a plant-based diet actually leaves you feeling sluggish. This could be due to missing certain nutrients. “Nutrient deficiencies can be common on a plant-based diet,” says dietitian Gianna Beasley, M.S., R.D., C.P.T. “The lack of vitamin B12 is strongly correlated with increased fatigue.” You see, B12 helps break glucose down into usable energy, so having too little of it can leave you feeling pretty “meh”—and it’s primarily found in animal-based foods like fish, beef, and eggs. As such, many plant-based eaters find supplementing with vitamin B12 helpful.

Read More: How to Tell If Your Fatigue Is Normal or Something More Serious

Another reason you might feel tired after going plant-based: You simply might not be eating enough. “When someone is transitioning to a plant-based diet, it’s not uncommon to experience a drop in overall food intake while learning this new way of eating,” Beasley says. “If someone is lacking in overall calories, fatigue is very common.” Try tracking your calories with an app like MyFitnessPal to make sure you’re taking in enough for your height, weight, gender, and age.  

2. You’ve Started Getting Headaches

Vitamin B12 doesn’t just support your energy levels; it can also keep headaches at bay. If your plant-based diet isn’t providing enough B12, as well as iron, it could turn into a literal pain in the neck. “It’s possible that, in the absence of animal proteins, someone may experience nutrient deficiencies in iron and vitamin B12, which can cause more frequent headaches,” says Beasley. While the link between B12 and headaches isn’t incredibly clear, one theory is that a lack of the vitamin raises levels of the amino acid homocysteine, which can damage the small blood vessels in the brain when too high. Meanwhile, iron deficiency can mean that less blood (and therefore less oxygen) reaches your brain.

In this case, it’s best to consult with your healthcare provider to determine whether your plant-based diet—and not some other issue—is the underlying cause of your headaches.

3. Your Hormones Are Off

If you’re female and have been feeling down, noticed changes in your menstrual cycle, or experienced a drop-off in your libido, it might be time to look at how your plant-based diet is impacting your hormones. According to dietitian Amanda Liptak, R.D.N., owner of Nutrient Rich Life, women—especially those in mid-life—are not always great candidates for vegan and vegetarian diets. “Many women in their 40s are in a constant state of stress,” she says. “When you add in experiencing changes in reproductive hormones, which decline for most women mid-decade, that makes managing nutrition in midlife way different than in your 20s and 30s.” Her conclusion: Midlife women are often better off eating more meat (particularly red meat), not less.

Read More: Which Type of Protein Powder Is Best for You?

“Some of the most important vitamins for women in their 40s are B vitamins, and they’re plentiful in meats like grass-fed beef, lamb, and bison,” Liptak says. “Vitamin B3 helps preserve adrenal function and supports stress. Meanwhile, vitamin B6 plays a large role in regulating your feel-good hormones serotonin and dopamine, in addition to supporting healthy libido.” Without enough of these, your hormone function can take a hit.

Getting enough protein is also critical for women’s ability to maintain healthy hormones for women—and that can be hard to do if you’re not eating meat, Liptak adds.

4. You’re Not Seeing Weight Loss Results

Eat more plants, lose more weight—right? Tons of studies have linked plant-based diets to weight loss. But surprisingly, ditching meat doesn’t always mean shedding pounds. Truth is, weight loss often comes down to eating enough protein, which can be a major challenge without animal foods. “I’ve seen many clients over the years that like the idea of becoming vegetarian but struggle to reach the optimal amount of protein in order to support their weight loss goals,” Liptak says. “This is mainly because many high-protein plant-based foods are also higher in carbohydrates.” 

If you’re finding it a serious slog to rack up sufficient protein from plants, you may want to consider reintroducing some meat, fish, or eggs. “It’s much easier to add a three- to four-ounce chicken breast, which offers 24 grams of lean protein, to your meal than to combine plant foods in order to reach this goal,” Liptak points out.

5. You’re Bloated…a Lot

As healthy as it is to get plenty of fiber in your diet, there’s a point at which this nutrient can become excessive, causing extra air to build up uncomfortably in your belly. “Bloating and gas can be a sign that someone is consuming too many plant-based foods, especially since plants contain a much higher fiber content than animal foods,” Liptak says. 

Read More: Are You Making These Common Hydration Mistakes?

Fortunately, if eating mostly plants is causing trouble buttoning up your jeans, there are steps you can take. Liptak suggests adding fermented foods (think kimchi, sauerkraut, miso) to promote the growth of beneficial bacteria that break down the digestive fibers that can cause bloating. Hydrating sufficiently can also keep things moving in your digestive tract, while taking time to chew your food thoroughly can also lighten the digestive load later on.  

6. You Struggle to Find Foods You Like (or You Really Just Miss Meat)

The right diet for you takes your personal preferences into account. If a plant-based diet doesn’t include foods you genuinely enjoy, you’ve got to ask yourself if the eating plan truly suits you. Constantly daydreaming of salmon or lusting after every cheeseburger you see might be signs that eating all-veg isn’t your ideal lifestyle.

That said, if you want to stay the course with a plant-based diet for health or environmental reasons, Beasley has a couple of suggestions. “If someone needs to adjust to a plant-based diet, I would recommend transitioning slowly,” she says. She also encourages experimenting with plant-based meat substitutes. “My best advice is to try different options to find your favorite and to go into each with an open mind, knowing it won’t be like eating actual meat.” 

How to Make Plant-Based Eating More Sustainable

A plant-based diet may be more environmentally sustainable—but you also have to consider how sustainable it is for you personally. Adopting plant-forward eating for the long run requires making it more convenient and enjoyable for yourself.

A few expert tips for making that a reality:

• Buy frozen veggies and fruits, bagged salads, bean soup blends, or pre-cooked grains as easy meal starters.
• Experiment with different cooking methods for various plant-based proteins, like grilling tofu or braising tempeh.
• Branch out! Stay open to trying plant-based foods from other cultures (or even ones you think you don’t like).
• Try to incorporate healthy fat, lean protein, and a source of fiber at every meal to promote feelings of fullness. Think garlicky beans and kale sautéed in olive oil or a tahini-drizzled grain bowl with chickpeas and sweet potatoes.
• Keep a food diary or track your meals on an app to get a sense of where your diet may be lacking.

Finally, if you end up deciding to switch back to eating animal products, whether regularly or just occasionally, take it slow. “When someone has been following a plant-based diet and wants to reincorporate meat products, I recommend reintroducing them slowly, one protein type at a time,” says Beasley. “Enzyme production decreases when you remove animal proteins, but you’re able to increase enzyme production with slow reintroduction.” 

And if you originally went veg to do your part for the environment or to minimize animal cruelty, you can always take steps to choose animal foods that have been responsibly raised. Shop farmer’s markets, look for pasture-raised or organic meats and dairy products, and don’t hesitate to ask your supermarket’s butcher about the quality and sustainability of the items behind their counter.