Sophie Macfie's 1.63M Instagram followers—but only 24% fitness content. Here's why brands are looking elsewhere.

The Follower Count Trap: What 1.63M Followers Actually Buys You

Sophie Macfie (@sophsplantkitchen) has 1.63 million followers on Instagram. She's a bestselling author, a qualified personal trainer, and based in London. On paper, she's the dream influencer for any fitness brand looking to go viral. But here's the catch: only 24% of her content is actually about fitness. The rest? Plant-based recipes, lifestyle shots, book promotions, and general wellness content that blurs the line between health and lifestyle.

If you're a sales professional or agency owner pitching a fitness supplement, a gym wear launch, or a high-protein snack, you're paying for 1.63 million eyeballs, but only 391,000 of them are seeing fitness-related posts. That's a 76% waste of your budget if you're targeting pure fitness enthusiasts. The Modash.io data, published just five days ago (May 2026), makes this painfully clear: follower count is a vanity metric when content purity is low.

This isn't about bashing Sophie Macfie—she's clearly built a massive, engaged audience around her broader brand. But for a targeted campaign, you need to match the creator's niche alignment to your product. Otherwise, you're burning budget on impressions that won't convert.

Content Purity: The Metric That Should Replace Follower Count in Your Pitch

Content purity measures what percentage of a creator's posts fall within a specific niche. For fitness, it's the ratio of fitness-related content to total content. The Modash.io list of 95 London fitness creators—38 on Instagram and 57 on TikTok—reveals a stark divide between popularity and relevance.

ABBIE DENNISON: The 93% Purity Champion

ABBIE DENNISON (@abbiedennisonfit) has 554,100 followers on Instagram—roughly a third of Sophie Macfie's audience. But her fitness content purity sits at 93%. That means nearly every post she creates is directly relevant to fitness: workouts, nutrition tips, competition prep, and Gymshark sponsorships (code 'ABBIE10'). She's also sponsored by ESN (code 'ABBIE') and has an upcoming event at Berlin HYROX on 28 May 2026.

For a brand launching a new protein bar or a recovery supplement, ABBIE DENNISON is the smarter bet. Her audience expects fitness content, so your product integration feels natural, not forced. The engagement rate on her fitness posts is likely higher because her followers are there for exactly that reason. You're not interrupting their scroll—you're adding value to their existing interest.

The Middle Ground: Kate Elisabeth at 67% Purity

Kate Elisabeth (@kateelisabethxo) has 245,300 followers and a 67% fitness content purity. She's also the founder of @kikakinis, a swimwear brand. That crossover means she can authentically promote both fitness apparel and lifestyle products. For a brand selling athleisure wear that doubles as swimwear, she's a perfect fit. The 67% purity tells you that while fitness is her primary focus, she has room to pivot into related niches without losing credibility.

The Low-Purity Risks: Nakita Johnson and LifewithLuisa

Nakita Johnson (@nakitajohnson39) has 377,300 followers on TikTok but only 17% fitness content purity. Her content covers family, beauty, and lifestyle. LifewithLuisa (@lifewithxluisax) has 212,200 followers on Instagram with 25% fitness purity—she's a British Latina foodie first. If you're selling a fitness product, these creators will struggle to make the connection feel authentic. Their audiences follow them for variety, not for workout tips. Your ad or sponsored post will feel like an interruption, and engagement will suffer.

Why TikTok and Instagram Demand Different Purity Thresholds

The Modash.io list covers 95 creators: 38 on Instagram and 57 on TikTok. That skew towards TikTok isn't accidental. Our previous analysis showed that TikTok's engagement hit 3.70% in 2025 while Instagram flatlined at 0.48%. Higher engagement means even a smaller, purer audience can drive more conversions than a larger, diluted one.

Emma Petersen (@thefitlondoner) has 466,100 followers on TikTok with 46% fitness content purity. She promotes her book 'Healthy-ish High Protein', which straddles the line between fitness and food. On TikTok, where the algorithm rewards niche consistency, her 46% purity might actually be an advantage—she can tap into both the fitness and foodie communities without confusing the algorithm. On Instagram, where the feed is more curated, that same mix might feel disjointed.

For your sales outreach, this means you need to adjust your purity expectations by platform. A creator with 40% fitness purity on TikTok can still drive viral reach because the platform's discovery engine surfaces content to interested users regardless of follower count. On Instagram, you want 60%+ purity to ensure your message lands in front of the right eyes.

How to Use This Data in Your Sales Pitch to Brands

If you're an agency or consultancy pitching creator collaborations to fitness brands, this data is your ammunition. Stop leading with follower count. Start leading with content purity and engagement context.

Build a Purity-First Pitch Deck

When you present a creator shortlist, include a purity percentage for each candidate. Show the brand how many of that creator's posts are directly relevant to their product category. For a protein supplement brand, ABBIE DENNISON at 93% purity is a stronger ROI than Sophie Macfie at 24%, even though the latter has three times the followers. Use the Modash.io data as a benchmark: the average fitness content purity across the 95 London creators is around 45%. Anything above 60% is a strong niche play.

Align Purity with Campaign Goals

If the brand wants broad awareness, a lower-purity creator with high follower count can work—but only if the product has lifestyle appeal. Sophie Macfie could successfully promote a plant-based protein powder because her audience already engages with plant-based content. But a hardcore pre-workout supplement? That needs ABBIE DENNISON's audience. Match the purity threshold to the product's specificity.

Use Event and Sponsorship Data to Validate Commitment

ABBIE DENNISON's upcoming Berlin HYROX event and her Gymshark sponsorship code signal deep industry involvement. She's not a casual fitness poster—she lives the lifestyle. That commitment translates to higher trust with her audience. When you pitch her to a brand, you're not just selling reach; you're selling credibility. The same logic applies to Emma Petersen's book promotion: she's invested enough in fitness to write a book about it. That's a signal of long-term niche alignment.

The Viral Trap: Why Low Purity Can Still Work (Sometimes)

Let's be honest: viral campaigns don't always need high purity. If your goal is to get millions of views for a brand awareness stunt, a creator like Nakita Johnson (377.3K TikTok followers, 17% fitness purity) can still deliver massive reach. Her content covers family, beauty, and lifestyle—broad appeal that can make a fitness product go viral if the creative is strong enough.

But here's the catch: viral views don't equal sales. Our analysis of creator ad spend hitting $43.9B showed that 87% of brands are still underspending their budgets because they can't tie creator content to conversions. Low-purity viral content drives impressions, not purchases. If you're selling a high-consideration product like a fitness subscription or a premium supplement, you need the trust that comes from a creator who lives and breathes fitness.

The smart play is a tiered strategy: use one high-purity creator (like ABBIE DENNISON) for conversion-focused content, and one broad-appeal creator (like Nakita Johnson) for awareness. But measure both against the same KPIs—don't let viral views distract from actual ROI.

Ready to Find Your Perfect Creator Match Without the Guesswork?

You've seen the data: follower count is a trap, content purity is the real signal, and platform context matters. But manually scraping Modash.io or Joli for every campaign is unsustainable. That's where MiraReach comes in. Our AI-powered platform automates prospect discovery, scores inbox engagement, and preps meeting notes so you can pitch the right creators to the right brands—without wasting hours on manual research.

Stop guessing which influencer will actually move the needle. See MiraReach plans and start building data-backed creator strategies that convert.

Frequently Asked Questions

What is content purity and why does it matter for influencer marketing?

Content purity measures the percentage of a creator's posts that fall within a specific niche, such as fitness. It matters because a high-purity creator has an audience that expects and engages with that type of content, making product integrations more effective and reducing wasted ad spend.

Who is the top London fitness influencer on Instagram by follower count?

Sophie Macfie (@sophsplantkitchen) leads with 1.63 million followers on Instagram. However, her fitness content purity is only 24%, meaning most of her content covers plant-based recipes and lifestyle topics rather than pure fitness.

How can I find fitness influencers with high content purity for my campaign?

Use tools like Modash.io or Joli to filter creators by niche and review their content purity percentage. Look for creators with 60% or higher purity in your target niche, and cross-reference their engagement rates on the platform you plan to use. For fitness, ABBIE DENNISON at 93% purity is a strong example.

Should I prioritise follower count or content purity when choosing an influencer?

Prioritise content purity for conversion-focused campaigns, especially if you're selling a niche product like supplements or gym wear. Use follower count for broad awareness campaigns where the product has lifestyle appeal. The best strategy often involves a mix of both, with clear KPIs for each.