From Knowing to Doing: The Psychology Behind Successful Dietary Change
It’s no secret that we all know what to do when it comes to healthy eating. We’re all aware of the foods we “should” eat, and the foods we “shouldn’t”: More vegetables, less sugar, cut back on processed foods. However, despite knowing what’s best for us, the majority of us still struggle to make lasting changes.
So why is that?
Dr. Jen Unwin, a psychologist specialising in metabolic diseases, often emphasises that information alone is rarely enough to create lasting habits. For behaviour change to happen, it needs more than knowledge: It requires the right psychological approach, a shift in mindset, and the motivation to act on that knowledge.
Today, I’m sharing the story of Margaret and Bill, a lovely couple who came to see me for help with dietary changes and weight loss. Their journey highlights how knowing what to do doesn’t always lead to action, but with the right support, hope, and small, actionable steps, lasting change is possible.
The Disconnect Between Knowledge and Action
Margaret and Bill came to see me in their late fifties, both struggling with weight gain, low energy, and aches and pains. Bill, a software developer, spent long hours in front of a computer, while Margaret, a retired nurse turned homemaker, found herself constantly battling with frozen shoulder and neck pain.
Margaret, in particular, knew a lot about nutrition. As a nurse, she had fairly good knowledge about what constitutes a balanced diet. She was aware that they should eat more fresh produce, avoid sweets and processed foods, and limit sugary snacks. However, despite her knowledge, implementing these changes was difficult. They had developed ingrained habits over the years that weren’t aligned with their health goals.
Here’s a look at their typical day:
- Breakfast: Coffee with sugar and rusks. Margaret loved a hearty start to the day, and Bill would usually have the same.
- Morning snack: Fruit salad (a healthy option) with wafer biscuits for crunch.
- Tea-time snack: Scones with jam and cream or grated cheese. Margaret was an excellent baker, so these homemade treats were a daily delight. Bill also enjoyed them with tea and honey.
- Lunch: A cooked meal of roast chicken or meat, potatoes, 2 vegetables, and gravy. Dessert was necessary for them — often an apple tart, custard Danish or crème caramel.
- Dinner: Soup with fresh bread and butter + cheese, followed by dark chocolate and a sherry while watching TV after dinner. Margaret’s sweet tooth had them indulge in dessert twice a day.
Despite their knowledge of healthy eating, this routine was full of foods that contributed to weight gain, insulin resistance, and low energy.
The Health Check: Knowledge Transforms into Hope
When we looked at their blood tests, it was clear that both were dealing with metabolic issues. Margaret had high levels of inflammation and was insulin-resistant, while Bill had fatty liver, high triglycerides, and high blood sugar levels — now in the diabetes range.
The turning point came when I explained to them that their aches and pains (especially Margaret’s frozen shoulder) were likely related to inflammation and metabolic factors, not just overuse or aging.
Understanding that lifestyle changes could improve their pain and health gave them hope — the belief that they could feel better without relying on medication. Hope, in this case, acted as a powerful motivator to turn their knowledge into action.
Turning Knowledge into Action: The Power of Practical Steps
While they had the knowledge of what to eat, it was time to take that knowledge and turn it into real change.
Here’s how we approached it:
- A High-Protein Breakfast
We swapped out their typical high-carb breakfast (coffee and rusks) for a high-protein breakfast that would stabilise their blood sugar levels and keep them full longer. Their new breakfast looked like this:
- Eggs
- Avocado
- Smoked salmon
- Seed crackers
By focusing on protein and healthy fats, they were able to start their day with stable energy, which helped reduce cravings later in the day.
- No More Mid-Morning Snacks
Previously, their morning routine involved scones with jam or grated cheese and tea with honey. I encouraged them to skip the snack and tea-time treats entirely. Instead, they could have nuts, cheese, or biltong if they were really hungry, providing healthy fats and protein.
- Simplifying Dessert
Margaret loved to bake, and both had a sweet tooth. Instead of their usual apple tart, sweet pastry or crème caramel for dessert after lunch and dinner, we switched to yoghurt and fruit. If they craved something sweet, they could still enjoy a piece of dark chocolate — but only when they really wanted it.
- Increasing Protein at Dinner
Both Margaret and Bill were used to a hearty mid-day meal, but their evening meals needed more protein and vegetables. We shifted to meals like grilled chicken with leafy greens, vegetable stir-fries with fish or lean meat, and low-carb savoury baking for snacks and sides.
- Getting Active: From Sedentary to Moving
As a software developer, Bill’s job required him to sit for long hours, and Margaret’s pain had made her less active. We set a goal for them to take a walk after dinner instead of sitting in front of the TV.
It wasn’t just about burning calories — it was about improving metabolism, enhancing mood, and supporting their joints.
Results: Seeing the Benefits of Change
Just 1 month into these changes, the results were already visible:
- Bill lost 2.5kg and 3cm around his waist.
- Margaret lost 2kg and 2cm around her belly, and her shoulder pain was gone.
They also reported feeling more energetic, and most importantly, they were more motivated to keep going. They even decided to make their evening walks a regular habit.
After 3 months, their blood tests had normalised without any need for medication. Bill’s fatty liver improved, and Margaret’s inflammation levels dropped.
The changes weren’t just physical; they were psychological too. They felt empowered, and their relationship with food had shifted from a source of comfort to a tool for health.
What Can We Learn From Margaret and Bill’s Journey?
- Information alone doesn’t create change — psychological factors, like hope, motivation, and a belief that change is possible, are what drive action.
- Actionable steps like meal planning, protein-focused breakfasts, and consistent movement help turn knowledge into tangible change.
- Tracking progress — like their weight loss, improvement in pain, and normalised blood tests — provides ongoing motivation to stay on track.
How to Bridge the Gap Between Knowledge and Action in Your Own Health Journey
- Reflect on Your Health Goals: What do you want to achieve? (For example: “I want to lose weight and improve my energy.”)
- Identify Barriers: What’s preventing you from acting on your knowledge? (Is it time, fear of failure, lack of confidence?)
- Set Small, Achievable Goals: Break your goal into smaller steps, like switching to a protein-rich breakfast or adding 10 minutes of movement a day.
- Get Support: Surround yourself with people who motivate and encourage you.
Homework: Create Your Action Plan
- Choose one area to focus on: Is it your diet? Exercise? Sleep?
- Start small: Begin with one simple change, like cutting out sugary snacks or adding vegetables to every meal.
- Track Your Progress: Use a journal or app to monitor your food, activity, and health markers.
- Celebrate every win: Every step forward is a step towards better health!
Remember:
Margaret and Bill’s story shows that knowledge alone isn’t enough… It’s about turning knowledge into action with hope, small steps, and the right support. If you’re ready to make sustainable changes, start with one small goal today and build from there.