Do Text Message Nudges Help With Weight Loss?

Your phone already buzzes with reminders and alerts. Could a few short messages also help with weight? Researchers have tested text message programs in trials with surprisingly consistent, if modest, results. This is general education, not medical advice.

The big review

In 2020, Skinner and colleagues published a systematic review with meta-analyses in Obesity Reviews on text message programs for weight loss and weight loss maintenance. It covered 15 studies with 2,705 participants. For the 12 studies aimed at weight loss (1,977 participants), people who received the texts lost about 2.3 kg (about 5 pounds) more than people in the comparison groups, with a range of roughly 1.4 to 3.2 kg.

• The messages usually covered goals, food choices, activity and self-monitoring.
• Many programs sent texts that were tailored to the person, or asked them to reply with their weight or progress.
• The effect on maintaining weight was smaller, and by later follow-up the difference was no longer clearly different from zero.

Other reviews agree, with smaller numbers

An earlier review of programs that kept in touch for longer found an average difference of less than 1 kg compared with control groups. Reviews also differ in which studies they include, so the exact figure moves. The takeaway is consistent: texts tend to help a little, mostly while the messages are flowing.

Why a simple text might work

• It prompts a decision at the right moment. A short message arrives when you can act on it.
• It supports self-monitoring. Reminders to log food, steps or weight keep awareness up. See our look at keeping a food journal.
• It feels personal. Tailored messages may feel more like a coach than a poster.

Limits to keep in mind

• The average hides a wide range. Some people respond well and others tune the messages out.
• Quality varies. A program with clear goals and feedback is different from random tips.
• Benefits may fade. Once messages stop, so might the effect, which is why a lasting habit matters more than the reminder. Our article on if-then plans describes one way to build that.

Making nudges work for you

You do not need a special service to try this. Set a few phone reminders that fit your goals, such as a walk after lunch or logging dinner, and keep them short and kind. Other digital tools have similar strengths, as we describe in the positive outcomes of using a weight-loss app and step challenges and badges.

Sources

• Skinner R, Gonet V, Currie S, Hoddinott P, Dombrowski SU. A systematic review with meta-analyses of text message-delivered behaviour change interventions for weight loss and weight loss maintenance. Obesity Reviews, 2020;21(6) (figures from the abstract).
• Job JR, et al. Review and meta-analysis of extended-contact text message interventions for weight management, Obesity Reviews (details from a summary; check the paper for exact figures).