Jump to: Core philosophies | Clinical evidence | Nutrition approach | Psychological approach | Support quality | Programme features | Pricing | Long-term outcomes | Member experiences | Who should choose which | Take home message
This article is accurate to the best of our knowledge as of May 2025.
Second Nature was created because we believe the traditional approach to weight loss needs fundamental change.
Research published in clinical journals shows that restrictive approaches like Slimming World’s Syns® and points systems create the psychological conditions for yo-yo dieting and weight regain.
While Joe Wicks’ programme offers a more positive focus on exercise and whole foods, its rigid meal timing and macro counting can still create an unsustainable relationship with food for many people.
At Second Nature, we take a different approach. Rather than just telling you what to eat (or avoid), we help you understand why you struggle with sustainable weight loss by combining behavioural psychology with nutritional science.
Our NHS-backed approach, published in the BMJ, shows that people maintain an average 6.2kg weight loss at 12 months: significantly better than most commercial weight loss programmes.
This comparison examines the clinical evidence, psychological impact, and long-term outcomes of each approach to help you make an informed decision about your weight loss journey.
Medication-assisted weight loss with a future focus
Start with Mounjaro, transition to habit-based health with our support
Core philosophies
The fundamental difference between these programmes lies in their underlying approach to weight loss.
| Programme | SW | JW | Second Nature |
| Primary method | Food categorisation system (Free Foods, Syns) |
Exercise-focused with macro counting (different for rest/workout days) |
Habit formation No counting or restriction |
| Food philosophy | Free foods vs ‘syns’ (creating moral labels) |
Cyclical carb approach (high/low carb days) |
No food is forbidden Focus on balance and satisfaction |
| Target audience | People seeking community support and structure | Fitness enthusiasts seeking rapid results | Those seeking evidence-based, sustainable change |
| Weight loss strategy | External rules Group accountability |
Intense exercise Strict meal plans |
Behavioural psychology Sustainable habit changes |
Clinical evidence
A significant difference between these programmes is their level of clinical validation and evidence base.
Second Nature’s NHS partnership
Second Nature has been working with the NHS since 2017. Our outcomes, published in the BMJ, show participants maintain an average 6.2kg weight loss at 12 months.
Additionally, 40% of type 2 diabetes participants reduced their HbA1c below diagnostic thresholds, demonstrating metabolic improvements beyond weight loss.
Slimming World evidence
A 2019 study showed 5.5% average weight loss at 12 months in diabetic patients attending Slimming World. However, independent research suggests restrictive approaches may create psychological conditions for weight cycling and long-term regain.
Joe Wicks evidence
While Joe Wicks’ approach incorporates evidence-based exercise principles, there are currently no peer-reviewed studies evaluating the long-term effectiveness of his 90-day plan. Results are primarily supported by anecdotal success stories rather than clinical research.
| Evidence type | SW | JW | Second Nature |
| Peer-reviewed studies | Limited independent research | No published outcomes | BMJ publication NHS validation |
| Long-term maintenance | Limited data available | Anecdotal evidence only | 6.2kg maintained at 12 months |
| NHS integration | Limited pilot programmes | Not currently used | Active partner since 2017 |
Nutrition approach
The nutritional philosophy underpinning each programme significantly impacts both results and your relationship with food.
| Programme | SW | JW | Second Nature |
| Dietary approach | Low fat with unlimited ‘Free Foods’ | Rest days: low carb, high fat Exercise days: high carb, low fat |
Whole food, higher protein, fibre, and healthy fats |
| Food categorisation | Free Foods, Healthy Extras, and Syns® | Macro-based categories with strict timing | No rigid categories or forbidden foods |
| Counting/point system | ✓ (Syns® system) |
✓ (Macro counting) |
✗ |
| Scientific basis | Limited (1990s low-fat approach) |
Partial (exercise science stronger than nutrition) |
Strong (BMJ-published outcomes) |
Psychological approach
The psychological framework of each programme significantly impacts long-term success and your relationship with food.
Why points, syns and macro counting create problems
BBC Radio 4 investigation findings
A BBC Radio 4 investigation “Slimming Groups and Eating Disorders” documented serious concerns from leading eating disorder specialists about commercial diet programmes, with experts describing approaches like Slimming World’s as potentially harmful to mental health.
The investigation documented multiple cases of people developing eating disorders after joining commercial diet programmes. Common patterns included:
- Extreme behaviours to meet weekly weigh-in targets
- Laxative abuse before weigh-ins
- Skipping meals and avoiding water before sessions
- Development of binge eating patterns
- Hospitalisation for severe eating disorders
Expert medical consensus
Leading eating disorder specialists expressed serious concerns:
Professor Chris Fairburn (Oxford University): “So, you are actually training people to do something that is likely to create an eating disorder.”
Dr Omara Naseem (Clinical Psychologist): “Someone who’s got a restrictive eating pattern shouldn’t be going to these groups. Absolutely not. It will lead to a relapse.”
While the investigation focused primarily on points-based systems like Slimming World’s, any approach that creates rigid food rules and external validation (like strict macro counting) can potentially contribute to problematic relationships with food and body image.
Research in eating behaviour demonstrates that labelling foods as ‘good’ or ‘bad’ (through points, syns, or strict macro counting) creates psychological restriction that often leads to:
- Obsessive thinking about forbidden foods
- Binge eating when ‘rules’ are broken
- Guilt and shame around food choices
- All-or-nothing mentality
The restriction-binge cycle
Clinical psychology research shows that dietary restraint paradoxically increases the likelihood of overeating. This explains why many people experience the yo-yo cycle with traditional diet programmes.
| Psychological factor | SW | JW | Second Nature |
| Food categorisation | Syns = guilt-inducing | Strict macros = rigid rules | No foods forbidden |
| Behavioural focus | External control (syns) | Exercise as compensation | Internal awareness |
| Long-term mindset | Dependency on system | 90-day transformation mentality | Sustainable habit formation |
| Emotional approach | Group validation Focus on weekly weigh-ins |
Motivational intensity Before/after pictures |
Understanding triggers Building intrinsic motivation |
Second Nature’s psychology-first approach
Our programme is built on behavioural science research showing that sustainable change comes from:
- Understanding emotional triggers for eating
- Building intrinsic motivation rather than external rules
- Creating positive associations with healthy foods
- Developing self-compassion around slip-ups
Unlike programmes that focus on what to restrict, we help you understand why you eat the way you do – addressing the root causes of weight challenges rather than just symptoms.
Support quality
The qualifications and training of support staff significantly impact programme effectiveness and safety.
| Support type | SW | JW | Second Nature |
| Qualified professionals | ❌ Company-trained consultants |
❌ App-based support team |
✅ Registered dietitians & nutritionists |
| Clinical oversight | ❌ | ❌ | ✅ NHS-affiliated clinicians |
| Personalised advice | Generic group sessions | Standard meal/workout plans | 1:1 coaching tailored to individual |
| Medical condition support | Limited | ❌ | ✅ Diabetes, PCOS, thyroid conditions |
Why professional qualifications matter: Registered dietitians and nutritionists undergo 3-4 years of university training in nutrition science, psychology, and clinical practice.
They can safely support people with medical conditions and provide evidence-based advice rather than following a script or relying on personal experience.
When you’re making significant changes to your eating patterns, having qualified support ensures you’re getting scientifically sound guidance that addresses your specific health needs.
Programme features
Each programme offers different tools and resources to support your weight loss journey.
| Feature | SW | JW | Second Nature |
| App | ✓ (2 separate apps) |
✓ | ✓ (comprehensive) |
| Education content | Limited nutrition information | Exercise-focused content | In-depth psychology and nutrition modules |
| Recipe library | ✓ (syn-focused recipes) |
✓ (macro-counted recipes) |
✓ (300+ balanced recipes based on whole foods) |
| Exercise videos | ❌ | ✓ (HIIT-focused) |
✓ (appropriate for all levels with a wide variety of options) |
| Sleep tracking | ❌ | ❌ | ✓ |
| Step tracking | ❌ | ❌ | ✓ |
| Habit formation tools | ❌ | ❌ | ✓ |
Pricing
When comparing costs, it’s essential to consider what’s included and the long-term value based on success rates.
| Programme | SW | JW | Second Nature |
| Monthly cost | £24/month digital £30/month (with meetings) |
£42/month | £28-£39/month (non-medication programme) |
| Qualified nutritionist support | ❌ | ❌ | ✅ |
| Same coach throughout | ❌ | ❌ | ✅ |
| Value comparison | Limited support for price | Highest cost, fixed duration | Includes professional support (£60-£100/hr privately) |
Cost per successful outcome analysis: While Second Nature may have a higher monthly cost than Slimming World, our success rate for sustained weight loss makes it more cost-effective than repeatedly joining programmes that don’t deliver long-term results.
The inclusion of registered dietitians and nutritionists (typically costing £60-£100 per private session) provides exceptional value.
Long-term outcomes
The ultimate test of any weight loss programme is whether people maintain their results long-term.
Weight maintenance statistics
Our BMJ-published research shows:
- 90% of Second Nature participants maintain weight loss at 12 months
- Average maintained weight loss: 6.2kg
In contrast, reviews of commercial diet programmes show that most participants regain ~80% of lost weight within 2-5 years.
Why Second Nature achieves better long-term results
Our approach focuses on the psychological and behavioural factors that drive sustainable change:
- Habit formation: We build automatic healthy behaviours rather than relying on willpower
- Flexible mindset: No forbidden foods means no guilt-driven binges
- Stress management: Addressing emotional eating at its root
- Gradual progression: Sustainable changes that become second nature
| Outcome measure | SW | JW | Second Nature |
| 12-month weight maintenance | Limited published data | No long-term data (90-day programme) |
90% maintain loss 6.2kg average |
| Relationship with food | Risk of ‘syn’ obsession | Rigid meal timing and macros | Healthy, balanced approach |
| Post-programme confidence | Dependent on group meetings | Often requires programme repetition | Independent healthy choices |
Member experiences
Here’s what people who have tried all three programmes report:
Sarah, 42, tried Slimming World for 18 months, Joe Wicks for 3 months, now on Second Nature:
“With Slimming World, I became obsessed with syns. I’d save them up for treats but then feel guilty. Joe Wicks’ plan worked initially but was too intense to maintain with my work schedule – I couldn’t keep up with the HIIT workouts and strict meal timing.”
“Second Nature taught me why I was comfort eating after stressful days. Now I make healthy choices naturally, without counting anything. I’ve maintained a 2 stone loss for over a year.”
Mark, 38, former Joe Wicks and Slimming World member:
“Joe’s workouts gave me great results initially, but the strict meal plan was impossible to maintain long-term. Slimming World’s group meetings felt shame-based when you hadn’t lost weight.
With Second Nature, my dietitian helped me understand my emotional eating patterns. I’ve learned skills I’ll use for life, not just while I’m paying for a programme.”
Who should choose which programme
Based on our analysis, here’s guidance on which programme might suit different needs:
Choose Slimming World if:
- You thrive in face-to-face group settings and community support
- You prefer a structured system with clear rules about what to eat
- You’re comfortable with food labelling approaches despite expert warnings
- You have no history of disordered eating or food anxiety
Choose Joe Wicks if:
- Exercise is your primary motivator for weight loss
- You enjoy high-intensity interval training
- You’re looking for a short-term transformation rather than a long-term lifestyle
- You’re comfortable with strict meal timing and macro counting
Choose Second Nature if:
- You want evidence-based, psychologically safe weight loss
- You’re looking for sustainable results rather than quick fixes
- You value support from qualified health professionals
- You want to understand why you eat the way you do, not just what to eat
- You have medical conditions that require expert nutritional guidance
- You’ve tried restrictive approaches before and experienced weight regain
Take home message
The fundamental difference between Second Nature and traditional weight loss programmes lies in our evidence-based, psychology-first approach that prioritises long-term sustainability:
- Clinical validation: Our NHS partnership and BMJ publication demonstrate real-world effectiveness
- Psychological safety: We avoid food labelling and restriction-based approaches that experts warn can trigger problematic eating patterns
- Professional oversight: Registered dietitians provide qualified, ongoing support
- Long-term success: 90% maintain weight loss at 12 months vs. high regain rates with traditional diets
- Comprehensive approach: We address stress, sleep, and emotional eating alongside nutrition
When choosing a weight loss programme, consider not just how quickly you’ll lose weight, but whether the approach promotes a healthy relationship with food and sustainable results.
Second Nature’s weight-loss programme
Second Nature combines evidence-based nutrition with behavioural psychology to help you lose weight and keep it off long-term.
Our approach has been validated by the NHS and published in the BMJ, showing that we’re the most trusted weight-loss programme in the UK.
Why should you choose Second Nature over other providers?
For peace of mind.
Second Nature has worked with the NHS for over 6 years, providing weight-loss programmes across the UK. Our programmes focus on scientific evidence, patient safety, and sustainable outcomes.
We hope that our track record of effective, evidence-based weight-loss results will give you peace of mind to give us a try.
