Jump to: The basics | Clinical evidence | Pricing | Psychological approach | Eating disorder risks | Support quality | Long-term outcomes | Convenience | Member experiences | Take home message
This article is accurate to the best of our knowledge as of May 2025.
Second Nature exists because we fundamentally disagree with Weight Watchers (WW) and Slimming World’s approach to weight loss.
Research published in clinical journals shows that restrictive approaches like points systems and food labelling create the psychological conditions for yo-yo dieting and weight regain.
A BBC Radio 4 investigation 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.
Unlike programmes that focus on what to restrict, Second Nature addresses why people struggle with sustainable weight loss.
Our NHS-backed approach, published in the BMJ, shows that people maintain an average 6.2kg weight loss at 12 months.
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.
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The basics
Trustpilot scores
Customer satisfaction scores reflect real user experiences and long-term success rates.
| Programme | WW | Slimming World | Second Nature |
| Score | 2.1/5 read reviews |
4.5/5 read reviews |
4.6/5 read reviews |
| Common complaints | Points obsession Weight regain |
Confusing syn system Food guilt |
Higher cost (but better outcomes) |
Core approaches
| Programme | WW | Slimming World | Second Nature |
| Primary method | PersonalPoints system Food tracking |
Free Foods + Syns Food categorisation |
Habit formation No counting |
| Food philosophy | Good/bad points values | Free foods vs syns | No food is forbidden |
| Qualified support | Group leaders (former members) |
Consultants (company trained) |
Registered dietitians & nutritionists |
Clinical evidence
The most significant difference between these programmes lies in their clinical validation and long-term outcomes.
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.
Weight Watchers evidence
While WW cites internal studies, independent research on commercial diet programmes shows that restrictive point systems often lead to weight cycling and psychological stress around food choices.
NHS referral concerns
The BBC investigation found that 23% of English councils refer patients to Slimming World, making it the largest single provider of NHS-funded weight loss services. However, screening for eating disorders is inconsistent:
- Only 2 out of 73 referral forms specifically mention binge eating
- Nearly half of forms include no eating disorder screening
- Beat charity reports that 23% of people seeking help for binge eating disorder had been recommended diet plans
NICE guidelines state that weight-loss programmes are not recommended for binge eating disorder and can actually be harmful.
These guidelines are why Second Nature has a strict screen process during our onboarding, along with safeguarding procedures overseen by our in-house team of dietitians and psychologists to delicately remove clients from our programme if we suspect they have an eating disorder.
| Evidence type | WW | Slimming World | Second Nature |
| Peer-reviewed studies | Limited independent research | No published outcomes | BMJ publication NHS validation |
| Long-term maintenance | High regain rates reported | Limited data available | 6.2kg maintained at 12 months |
| NHS integration | Not currently used | Limited pilot programmes | Active partner since 2017 |
Pricing
When comparing costs, it’s essential to consider what’s included and the long-term value based on success rates.
| Programme | WW Digital | Slimming World | Second Nature | Value Analysis |
| Monthly cost | £10-£19 | £20-£24 (meetings + digital) |
£28-£39 (non-medication programme) |
– |
| Qualified nutritionist support | ❌ | ❌ | ✅ | Private dietitian: £60-£100/session |
| Sustained weight loss at 12 months | Low success rate | Limited data | Average 6.5kg loss | Cost per successful outcome |
| NHS clinical backing | ❌ | ❌ | ✅ | Peace of mind |
Cost per successful outcome analysis: While Second Nature has higher upfront costs, our success rate for sustained weight loss makes it more cost-effective than repeatedly joining programmes that don’t deliver long-term results.
Psychological approach
The psychological framework of each programme significantly impacts long-term success and relationship with food.
Why points and syns create problems
Research in eating behaviour demonstrates that labelling foods as ‘good’ or ‘bad’ (through points or syns) 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 | WW | Slimming World | Second Nature |
| Food categorisation | Points = moral value | Syns = guilt-inducing | No foods forbidden |
| Behavioural focus | External control (points) | Rule-based eating | Internal awareness |
| Long-term mindset | Dependency on system | Fear of ‘syns’ | Autonomous healthy choices |
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
Support quality
The qualifications and training of support staff significantly impact programme effectiveness and safety.
| Support type | WW | Slimming World | Second Nature |
| Qualified professionals | ❌ Former members become leaders |
❌ Company training only |
✅ Registered dietitians & nutritionists |
| Clinical oversight | ❌ | ❌ | ✅ NHS-affiliated clinicians |
| Personalised advice | Generic group sessions | Group-based guidance | 1:1 coaching tailored to individual |
| Medical condition support | ❌ | ❌ | ✅ Diabetes, PCOS, thyroid conditions |
Why professional qualifications matter: Registered dietitians undergo 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.
Eating disorder risks and safeguarding
A critical difference between these programmes lies in their approach to eating disorder prevention and detection.
Documented eating disorder concerns
The BBC Radio 4 investigation “Slimming Groups and Eating Disorders” 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.”
| Safeguarding approach | WW | Slimming World | Second Nature |
| Eating disorder screening | Basic self-reporting | Inconsistent screening | Clinical assessment by qualified professionals |
| Ongoing monitoring | ❌ | ❌ | ✅ Regular dietitian check-ins |
| Professional oversight | ❌ | ❌ | ✅ NHS-trained clinicians |
| Approach to rapid weight loss | Often celebrated | Rewarded with certificates | Medically supervised for safety. Dietitian’s will intervene if weight loss is beyond a sustainable level of 1-2lbs a week. |
Second Nature’s clinical safeguards
Our NHS-backed approach includes multiple safeguards absent from commercial diet programmes:
- Professional screening: All participants assessed by qualified health professionals
- Ongoing clinical oversight: Regular monitoring by registered dietitians trained to identify eating disorder symptoms
- Psychology-first approach: Focus on understanding eating behaviours rather than restricting foods
- No food labelling: We never categorise foods as ‘good,’ ‘bad,’ or assign moral values
- Sustainable targets: Weight loss goals based on medical evidence, not arbitrary weekly targets
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 | WW | Slimming World | Second Nature |
| 12-month weight maintenance | Low success rates (high regain common) |
Limited published data | 90% maintain loss 6.2kg average |
| Relationship with food | Often becomes obsessive | Fear of ‘syn’ foods | Healthy, balanced approach |
| Post-programme confidence | Dependent on points system | Reliant on group meetings | Independent healthy choices |
Convenience and flexibility
| Feature | WW | Slimming World | Second Nature |
| Time commitment | High (constant tracking) |
Medium (weekly meetings) |
Low (habit-based) |
| Mental energy required | High (calculating points) |
Medium (remembering syns) |
Low (intuitive choices) |
| Social eating flexibility | Difficult (need to calculate) |
Limited (syn counting) |
Easy (mindful choices) |
| Travel adaptability | Challenging | Difficult | Flexible |
Member experiences
Here’s what people who have tried all three programmes report:
Sarah, 42, tried WW for 2 years, Slimming World for 18 months, now on Second Nature:
“With Weight Watchers, I became obsessed with points. I’d save them up for wine but then feel guilty. Slimming World was confusing – calling chocolate ‘syns’ made me feel like I was doing something wrong just for enjoying a treat.”
“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 Slimming World member:
“The 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.”
Take home message
The fundamental difference between Second Nature and traditional diet programmes lies in our evidence-based, psychology-first approach that prioritises safety and long-term mental health:
- 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 eating disorders
- Professional oversight: Registered dietitians provide qualified, ongoing clinical supervision
- 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
- Evidence-based safety: Unlike programmes investigated by the BBC for potential eating disorder risks, our approach is designed with psychological safety as a priority
Choose Weight Watchers if: You prefer structure and don’t mind ongoing tracking, and have no history of eating disorders or food-related anxiety.
Choose Slimming World if: You thrive in group settings despite expert warnings about food labelling approaches, and have no eating disorder risk factors.
Choose Second Nature if: You want evidence-based, psychologically safe weight loss supported by NHS-validated outcomes and qualified professionals who understand the importance of sustainable behaviour change without food restriction or moral labelling.
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.
