The right chart design can make your data more persuasive, memorable, and actionable.
When it comes to fitness advice, Nerd Fitness is one of my go-to sources. They cut through the noise with science-backed guidance, relatable coaching, and actionable steps that fit real life.
In a recent newsletter, they tackled an important but often misunderstood topic:
How much muscle do you actually lose when you’re losing weight?
Their message was clear, you’re never going from “all muscle loss” to “no muscle loss”.
- Lean mass loss is always part of weight loss.
- The size of your daily calorie deficit matters.
- Strength training and protein intake can help you keep more muscle.
The only problem was the chart they used to illustrate this point was not doing their great message justice.
Before: A Chart That Makes You Work Too Hard
The original chart was a 100% stacked bar chart with:
- No direct labels for the actual percentages
- Colors that made it difficult to quickly separate “lean mass” from “fat mass”
- An arrangement that made it hard to compare differences between strength training and no training scenarios
While technically accurate, the chart required the reader to slow down and decode it which is something that just doesn’t work well in today’s fast-scrolling, short-attention-span world.
After: A Diverging Bar Chart That Highlights the Main Point
As a data visualization designer, I reworked the chart into a diverging bar chart to focus on what really matters, the percentage of lean mass lost at different calorie deficits, depending on whether strength training is involved.
Here’s what changed in the redesign:
- Lean mass loss is now anchored from the center so the percentage is immediately visible and comparable.
- Clear labeling makes the numbers readable at a glance.
- Consistent, intuitive color choices separate lean mass loss from fat loss without confusion.
- Animation to make the story memorable.
- Headline to highlight the most important point.
Why this matters for storytelling.
Charts aren’t just decoration they’re part of the story. A well-designed chart can:
- Cut through fear-mongering myths (like "no strength training results in all muscle loss")
- Highlight actionable insights (like “strength training can save 10–15% more muscle”)
- Build trust by making the data clear and transparent
By switching from the original stacked bar chart to a diverging bar chart, the story became instantly obvious:
- More calorie deficit = more lean mass loss
- Strength training always improves the ratio of fat to muscle loss
- It's never 100% muscle and it's never 0% muscle, real results are in between
Why Diverging Bars Win the Redesign
- Focus on one main takeaway
- Use percentages and labels directly on the bars
- Make comparison between scenarios simple
- Clarity - Instantly see the difference without mental math
- Focus - The main insight is front and center, not buried in the narrative
- Speed - It tells the story in under 3 seconds of viewing