Breast cancer survivors often struggle with weight gain due to cancer treatments and menopause, which can increase the risk of cancer returning. Researchers tested a 24-week program using a mobile app called Noom combined with personal coaching to help 130 breast cancer survivors lose weight. Most participants who stayed engaged with the program lost weight, improved their cholesterol levels, and felt better about their bodies. The weight loss stayed off for a full year without the typical yo-yo effect of gaining it back. This suggests that combining an app with real human support may be an effective way for cancer survivors to manage their weight and improve their overall health.

The Quick Take

  • What they studied: Whether a mobile app combined with a personal coach could help breast cancer survivors who are overweight lose weight and improve their health markers over 24 weeks.
  • Who participated: 130 breast cancer survivors (average age 55) who were overweight or obese. Most were women who had completed cancer treatment. About 71% finished the full 12-month study.
  • Key finding: Among the most engaged participants, weight dropped by about 2 kg (4.4 lbs) and stayed off for a full year. Triglyceride levels (a type of fat in the blood) also decreased significantly and remained lower at 12 months.
  • What it means for you: If you’re a breast cancer survivor struggling with weight, combining a weight-loss app with personal coaching may help you lose weight safely and keep it off. However, this study only looked at people who actively used the program, so results may vary for others.

The Research Details

This was a single-arm prospective cohort study, which means researchers followed one group of people over time without comparing them to a control group. All 130 breast cancer survivors received the same 24-week program using the Noom app combined with personalized coaching from trained coaches. The program included lessons about healthy eating, exercise routines, and mental health support. Researchers measured participants’ weight, body composition (muscle vs. fat), cholesterol levels, and quality of life at the start, after 6 months, and after 12 months. They focused their main analysis on the 68 participants who were most engaged with the program (used it for more than 16 weeks).

This research design allows researchers to see real-world results in actual cancer survivors dealing with the specific challenges they face. By including both diet, exercise, and psychological support, the study tests a comprehensive approach rather than just one strategy. Following people for a full year helps determine if weight loss is temporary or lasting.

The study had a good completion rate (71.5% finished 12 months), which is important for reliability. However, because this was a single-arm study without a comparison group, we can’t be certain the app and coaching caused the results—other factors could have contributed. The researchers focused on the most engaged participants, which may make results look better than they would be for everyone who starts the program.

What the Results Show

Among the 68 most engaged participants, body weight decreased by an average of 1.97 kg (about 4.4 pounds) after 6 months, and this weight loss was maintained at 12 months without bouncing back. BMI (a measure of weight relative to height) also decreased significantly and stayed lower. These results suggest the program helped people lose weight in a sustainable way rather than the typical pattern of losing weight quickly and gaining it back. Triglyceride levels, which are a type of fat in the blood linked to heart disease, dropped by an average of 34 mg/dL and remained lower at the 12-month mark. This is important because breast cancer survivors are at higher risk for heart disease, so improving these levels may provide additional health benefits.

Body composition improved in the first 6 months, with participants gaining muscle and losing fat. However, some measures like waist-to-hip ratio and visceral fat (dangerous fat around organs) increased slightly between months 6 and 12, suggesting the benefits may plateau or require continued effort. Quality of life improved significantly, with participants reporting less nausea, better digestion, improved body image, and fewer arm and breast symptoms—all important for cancer survivors’ well-being.

Previous research shows that weight gain after breast cancer treatment is common and increases recurrence risk. This study adds to growing evidence that mobile apps combined with human coaching may be more effective than apps alone. The finding that weight loss was maintained for a full year is encouraging, as many weight-loss programs show weight regain after 6 months.

This study only included people who actively used the program, so results may not apply to those who struggle with engagement. Without a comparison group (like people using the app without coaching or people receiving no intervention), we can’t be completely certain the app and coaching caused the improvements. The study was conducted between 2019-2021, so some technology may have changed. Results may differ for people with different types of breast cancer or those still undergoing treatment.

The Bottom Line

If you’re a breast cancer survivor who is overweight or obese, a mobile app-based program combined with personal coaching appears to be a reasonable option to try (moderate confidence). The program seems most effective for people who actively engage with it. Discuss this approach with your oncologist or healthcare provider to ensure it’s appropriate for your specific situation. Results suggest you might expect to lose 2-4 pounds over 6 months and maintain that loss if you stay engaged.

This research is most relevant for breast cancer survivors who are overweight or obese and want to lose weight to reduce recurrence risk. It may be particularly helpful for those who struggle with traditional weight-loss programs or who want personalized support. People still undergoing active cancer treatment should consult their doctor before starting. Those with very limited access to smartphones or internet may find this approach challenging.

Based on this study, you might expect to see weight loss within the first 6 months if you actively engage with the program. The key finding is that weight loss appears to be maintained at 12 months, suggesting this isn’t a quick fix but rather a sustainable approach. However, some benefits (like improvements in visceral fat) may require ongoing effort beyond the initial 24 weeks.

Want to Apply This Research?

  • Track weekly weight and waist circumference measurements. Also monitor triglyceride levels through blood work every 3-6 months with your doctor. Record engagement metrics like days per week using the app and number of coaching sessions completed to correlate with weight changes.
  • Start by logging all meals and snacks for one week to build awareness, then gradually implement one dietary change per week (like reducing sugary drinks or adding vegetables to meals). Combine this with 150 minutes of moderate exercise weekly and schedule weekly check-ins with your coach to maintain accountability.
  • Use the app’s built-in tracking features to log daily food intake and exercise. Set weekly goals rather than focusing only on the final number. Track how you feel (energy levels, mood, symptoms) alongside weight metrics. Schedule monthly reviews with your coach to adjust the program if needed and celebrate non-scale victories like improved energy or better-fitting clothes.

This research describes results from a specific study and should not be considered medical advice. Breast cancer survivors considering weight-loss programs should consult with their oncologist or primary care physician before starting, especially if they are still undergoing cancer treatment or taking medications that affect weight. Results may vary based on individual factors including type of cancer treatment, current medications, and overall health status. This study focused on people who actively engaged with the program; results may differ for others. Always seek professional medical guidance before making significant changes to diet, exercise, or health management.