Researchers studied 223 people newly diagnosed with type 2 diabetes who followed an extreme low-calorie diet (eating only 300-600 calories per day for 9 days). They discovered that a simple electrical test measuring how well your cells work could predict who would successfully improve their insulin resistance—a key marker of diabetes control. About 62% of participants improved significantly, and the test worked better for men than women. This finding suggests doctors might use this quick test to identify which patients will benefit most from strict dieting.

The Quick Take

  • What they studied: Can a simple electrical body scan predict whether someone with newly diagnosed type 2 diabetes will improve their blood sugar control when following an extreme low-calorie diet?
  • Who participated: 223 people (139 completed the study) who were just diagnosed with type 2 diabetes. They came from a hospital in China between 2021 and 2023. All were willing to eat only 300-600 calories per day for 9 days.
  • Key finding: A measurement called ‘phase angle’—obtained from a painless electrical scan—could predict success in men with about 73% accuracy. Men with higher phase angles were 6 times more likely to improve their insulin resistance. The test was less reliable for women.
  • What it means for you: If you’re a man newly diagnosed with type 2 diabetes, this test might help your doctor predict whether an extreme diet will work for you. However, this is early research, and the test didn’t work as well for women. Talk to your doctor before starting any extreme diet, as 300-600 calories per day is very restrictive.

The Research Details

Researchers enrolled 223 people with newly diagnosed type 2 diabetes who agreed to follow a very strict diet (eating only 300-600 calories daily for 9 days). Before starting the diet, each person received a painless electrical scan called bioelectrical impedance analysis, which measures how well your cells are functioning by sending tiny electrical signals through your body. This measurement is called ‘phase angle.’ After the 9-day diet, researchers checked if patients improved their insulin resistance—a key measure of diabetes control. They used statistical methods to see if the initial phase angle measurement could predict who would improve.

The study was conducted at a hospital in China from 2021 to 2023. All participants completed the full 9-day program, and no one experienced serious side effects like dangerously low blood sugar or kidney problems. The researchers compared results between men and women separately because they suspected the test might work differently for each group.

This research approach is important because it looks for early warning signs (called biomarkers) that could help doctors personalize treatment. Instead of having everyone try the same extreme diet, doctors could use this simple test to identify who is most likely to benefit. This could save time and help people avoid unnecessary suffering from restrictive diets that won’t work for them.

The study has several strengths: all 223 participants completed the program (good compliance), no serious side effects occurred, and the researchers used established statistical methods. However, the study is relatively small and was conducted in only one hospital in China, so results may not apply to all populations. The test worked much better for men than women, suggesting it may not be equally useful for everyone. The study is recent (2025) but hasn’t yet been reviewed by other scientists in published responses.

What the Results Show

Of the 223 people who started the study, 139 (about 62%) successfully improved their insulin resistance to the target level after the 9-day diet. These people also lost weight and improved their blood sugar control. The phase angle measurement taken before the diet was a strong independent predictor of success—meaning it predicted outcomes even when accounting for other factors like age or starting weight.

For men, the phase angle test was quite accurate. Men with a phase angle above 6.45 degrees were 6.3 times more likely to improve their insulin resistance. The test correctly identified success 67% of the time and correctly identified failure 77% of the time. For women, however, the test was much less reliable—it only worked slightly better than random chance (59% accuracy).

Interestingly, people whose phase angle decreased during the diet were less likely to maintain improvements, suggesting that maintaining cell health during extreme dieting is important for long-term success.

All participants showed improvements in body weight and blood sugar measurements after the diet. No one experienced dangerous side effects like severe low blood sugar, kidney problems, or liver damage—important findings since such extreme dieting carries risks. The good safety profile suggests that under medical supervision, this 9-day approach can be done safely, at least in the short term.

Phase angle has been studied as a health marker in other conditions, but this appears to be one of the first studies examining it specifically for predicting diabetes diet success. Previous research shows phase angle reflects cell membrane quality and overall cellular health, which makes biological sense for predicting metabolic improvements. However, most previous studies haven’t shown such strong gender differences, making this finding noteworthy and worth investigating further.

The study has several important limitations. First, it only lasted 9 days, so we don’t know if improvements last longer. Second, the study was conducted in one hospital in China, so results may not apply to other populations or countries. Third, the test worked well for men but poorly for women, limiting its usefulness. Fourth, 84 people started but didn’t complete the study, and we don’t know why or how they differed from those who finished. Finally, the study didn’t compare this test to other methods of predicting diet success, so we don’t know if it’s better than simpler approaches.

The Bottom Line

For men newly diagnosed with type 2 diabetes: This test may help your doctor predict whether an extreme low-calorie diet will improve your insulin resistance. However, this is early research, and you should only attempt such a restrictive diet under close medical supervision. For women: This test is not yet reliable enough to guide treatment decisions. For everyone: Before starting any extreme diet, discuss with your doctor whether it’s appropriate for you, as 300-600 calories per day is very restrictive and may not be safe long-term.

This research is most relevant for men with newly diagnosed type 2 diabetes considering extreme dieting under medical supervision. It may interest healthcare providers looking for tools to personalize diabetes treatment. It’s less relevant for women at this time, since the test didn’t work well for them. People with long-standing diabetes, those taking certain medications, or those with other health conditions should consult their doctor before applying these findings.

In this study, improvements appeared within 9 days. However, we don’t know if these improvements last weeks, months, or years. Most people would need to continue healthy eating habits to maintain benefits. Realistic expectations: if the test predicts you’ll respond well, you might see improvements in insulin resistance within days to weeks, but maintaining these improvements requires ongoing lifestyle changes.

Want to Apply This Research?

  • If your doctor performs a phase angle test, track the numerical result and date. Then monitor your insulin resistance score (HOMA-IR) or fasting blood sugar weekly. Create a simple chart showing how phase angle correlates with your blood sugar improvements over time.
  • Use the app to log your daily calorie intake if attempting a restricted diet (with doctor approval). Set reminders for medical check-ins, since extreme dieting requires supervision. Track any side effects or how you feel daily. If you have a phase angle test result, use it as motivation if your doctor predicts you’ll respond well to dietary changes.
  • Schedule regular blood work (fasting glucose and insulin levels) to calculate your insulin resistance score. Compare results before and after any dietary intervention. If attempting a restricted diet, have weekly check-ins with your healthcare provider. Track weight, energy levels, and blood sugar readings daily. If your phase angle is measured again, compare it to your baseline to see if cell health is improving.

This research is preliminary and should not replace professional medical advice. A phase angle test is not yet standard clinical practice for predicting diet success. Very low-calorie diets (300-600 calories per day) are extreme and potentially dangerous without medical supervision. This study only lasted 9 days, so long-term safety and effectiveness are unknown. If you have type 2 diabetes or are considering any restrictive diet, consult your doctor or registered dietitian before making changes. The test worked much better for men than women, so its usefulness varies by gender. Do not start this diet without professional medical oversight, as it carries risks including nutrient deficiencies, muscle loss, and metabolic complications.