【Summer Diet Survey】Nearly 40% Experience Health Issues Despite Efforts: The Hidden Pitfalls of Summer Dieting

Introduction

Japan's summer heat has become increasingly severe, as evidenced by the Japan Meteorological Agency's formal definition of 'extreme heat days' in April this year. Nwith Inc. (headquartered in Chuo Ward, Tokyo; CEO: Tatsuto Fukuzawa) conducted a 'Survey on Summer Dieting and Eating Habits' targeting 200 women aged 30–60 who have prior dieting experience, aiming to reveal the realities of dieting and eating habits during such extreme heat.

The results show that many women continue dieting during summer, with walking being the most popular method (73%). However, nearly 40% experienced health issues, suggesting that poor eating habits during summer may be a contributing factor. Additionally, 66.5% of respondents felt that 'maintaining a balanced diet is difficult to achieve alone.'

Survey Summary

・Top diet method: 'Walking' (73%), with 62.2% continuing during summer

However, the survey reveals a reality where effort does not always translate into results.

・Nearly 40% of women who continued dieting in summer experienced health issues

The more they push themselves, the more their bodies suffer—highlighting the hidden risks of summer dieting.

・Approximately 50% responded that they 'did not see the desired results'

Effort does not always lead to results. The challenges of summer dieting have become evident through this survey.

・66.5% feel that 'maintaining a balanced diet is difficult to do alone'

During extreme summer heat, it may not be necessary to try to manage your diet perfectly on your own.

Survey Details

'Women Who Continue Dieting in Summer'

This survey found that 81.6% of women have prior dieting experience. Among them, 200 women with dieting experience were surveyed. The most common diet method was walking (73%), followed by carbohydrate restriction (47.4%) and strength training (41.7%).

Even during extreme summer heat, 62.2% continued dieting, indicating that many women persist in their efforts despite the heat.

'However, nearly 40% experienced health issues, and about 50% did not feel results'

35.6% of women who continued dieting in summer experienced health issues, and nearly 50% did not feel they achieved their desired results. While over 60% of women who dieted in summer continued their efforts, nearly 40% experienced health issues—a reality that highlights the risks of summer dieting.

The harsh reality of summer dieting—persisting without results despite not giving up in the heat—has been revealed.

'The Pitfall of 'Not Eating' Diets'

57.4% of women reported decreased appetite during summer. It's easy to assume that eating less due to low appetite contributes to weight loss, but this may actually lead to health issues.

[Testimonials]

A (woman in her 50s): After trying various diets such as meal replacement, personal gyms, and esthetic salons with little change in weight, she incorporated dietary management under the guidance of a registered dietitian and saw a 4kg change within about four months.

B (woman in her 40s): After trying multiple 'not eating' diets such as fasting and auricular acupuncture dieting without desired results, she focused solely on dietary management without exercise and lost nearly 2kg within about four months.

C (woman in her 40s): After continuing exercise-based diets such as personal training and hot yoga for over six months, she added dietary management. Without changing her exercise routine, she saw nearly 2kg of body change within about two months.

*These are individual experiences and results may vary.

*Results are not guaranteed.

[From a Registered Dietitian]

Due to summer heat, appetite naturally decreases, and some may believe 'eating less leads to weight loss.' However, extreme dietary restrictions can negatively impact metabolism and energy consumption.

Furthermore, insufficient intake of essential nutrients such as carbohydrates, protein, vitamins, and minerals—necessary for metabolism—can lead to poor energy utilization, fatigue, sluggishness, and health issues.

'Not eating' does not necessarily lead to successful dieting. Maintaining metabolism while supplementing necessary nutrients is essential for healthy body management during summer.

Comment from CHONPS Registered Dietitian

Satoko Ogawa (Registered Dietitian)

Joined a school meal catering company after graduation, responsible for specific health guidance, menu planning, and cooking operations. Supported health initiatives for corporations and schools, promoting health management through diet.

Later transitioned to a company specializing in supplements and protein for athletes, providing nutritional guidance for both professional and amateur athletes. Participated in launching the company’s own café and managed menu planning and dietary operations for athlete dormitories. Currently working as a freelancer, providing dietary guidance through CHONPS, nutritional guidance and menu planning for unlicensed daycare centers, and conducting nutrition lectures and cooking classes. Also active in lectures at public elementary and junior high schools, specific health guidance, and column writing.

It is actually very difficult to eat balanced meals properly at every meal when appetite is low.

Therefore, the key is to consciously supplement 'minimum essential nutrients.' In particular, carbohydrates as an energy source, protein to support muscles and metabolism, and vitamins and minerals to regulate body functions are indispensable for summer health management.

Recommended: consciously include fruits and seaweed. Even if appetite is low in the morning, try eating fruit. At lunch or dinner, topping cold tofu with mozuku or making onigiri wrapped in nori can help supplement nutrients with relatively low effort.

Shifting focus from 'what to reduce' to 'what to supplement' is the key to continuing dieting without strain while preventing summer fatigue and health issues.

Summary

'66.5% of women feel it is difficult to manage their diet alone'

This survey also revealed that 66.5% of women feel it is difficult to manage their diet on their own. During extreme summer heat, reviewing and adjusting one’s eating habits to suit individual needs may be a crucial step to continue dieting while protecting one’s health.

CHONPS will continue to provide dietitian-led, supportive dietary assistance to continuously support nutritional management.

CHONPS/Chonps Recommends Personalized Meals for Everyone

CHONPS provides online dietary guidance services supervised by registered dietitians, offering personalized meal plans tailored to individual health conditions and food preferences. Through daily meal advice, we support both food waste reduction and healthy eating habits.

We boast approximately 12,000 dedicated registered dietitians, with only 6% selected through a rigorous hiring process to support your dietary improvements. All application development is done in-house, thoroughly pursuing ease of use and sustainability. Because dietitians are involved in app development, dietary guidance, and support, users can engage with confidence, supported toward long-term dietary improvements.

[Survey Overview]

Target: Women aged 30–60
Survey