# Real‐World Weight Loss Is Associated With a Reduction in Cancer Risk

## TL;DR

Losing weight in real life is linked to a lower risk of developing cancer, especially obesity-related cancers, over several years.

## Contribution

This study shows that modest nonsurgical weight loss reduces cancer risk over 3- to 10-year periods in real-world settings.

## Key findings

- Each 1% BMI reduction was associated with a lower risk of obesity-related cancer at 3 and 5 years.
- Weight loss also reduced the risk of other cancer types across all time intervals.
- The association remained significant for 3- and 5-year periods but was less clear at 10 years.

## Abstract

Obesity is a major risk factor for multiple cancers, yet the impact of nonsurgical weight loss on cancer risk remains uncertain. Our objective was to evaluate whether real‐world nonsurgical weight loss is associated with a reduced risk of developing cancer.

We conducted a retrospective observational study of 143,630 adults (BMI ≥ 30) from an integrated US health system's electronic health records (2000–2022). Cases with incident cancer were compared to matched controls. Using generalized linear models with a logit link, we assessed whether BMI change over 3‐, 5‐, and 10‐year intervals is associated with the risk of diagnosis for obesity‐related and other cancers.

Among 143,630 patients, 7703 cases and 135,927 controls were identified. Each 1% BMI reduction was linked to lower obesity‐related cancer risk at 3 years (OR, 0.990; 95% CI, 0.984–0.996; p < 0.001), 5 years (OR, 0.989; 95% CI, 0.984–0.995; p < 0.001), and 10 years (OR, 0.992; 95% CI, 0.984–1.000; p = 0.057). Similar associations were observed for other cancer types across all intervals (OR < 1; p < 0.001).

Real‐world weight loss was associated with a decreased risk of obesity‐related and other cancers.

What is already known?○Obesity is a well‐established risk factor for multiple types of cancer, but the impact of nonsurgical real‐world weight loss on cancer risk remains unclear.
What does this study add?○This study shows that even modest real‐world weight loss is associated with significantly reduced odds of both obesity‐related and other cancers over 3‐, 5‐, and 10‐year intervals.
How might these results change the direction of research or the focus of clinical practice?○These findings emphasize the importance of implementing effective weight loss interventions as part of cancer prevention strategies in routine clinical care.

What is already known?○Obesity is a well‐established risk factor for multiple types of cancer, but the impact of nonsurgical real‐world weight loss on cancer risk remains unclear.

Obesity is a well‐established risk factor for multiple types of cancer, but the impact of nonsurgical real‐world weight loss on cancer risk remains unclear.

What does this study add?○This study shows that even modest real‐world weight loss is associated with significantly reduced odds of both obesity‐related and other cancers over 3‐, 5‐, and 10‐year intervals.

This study shows that even modest real‐world weight loss is associated with significantly reduced odds of both obesity‐related and other cancers over 3‐, 5‐, and 10‐year intervals.

How might these results change the direction of research or the focus of clinical practice?○These findings emphasize the importance of implementing effective weight loss interventions as part of cancer prevention strategies in routine clinical care.

These findings emphasize the importance of implementing effective weight loss interventions as part of cancer prevention strategies in routine clinical care.