Research shows that older men with prediabetes who ate higher protein (1.4 grams per kilogram of body weight) while losing weight preserved significantly more muscle mass and showed better improvements in strength and walking ability compared to men eating standard protein amounts. According to Gram Research analysis of this randomized controlled trial, the enhanced protein group lost only 0.8 kilograms of muscle at 6 months versus 1.5 kilograms in the standard protein group, while also walking farther and maintaining stronger grip strength.
A new study shows that older men with prediabetes who ate more protein while losing weight kept more muscle and stayed stronger than those eating standard protein amounts. Researchers at a veterans facility tested two groups of men over 55 with obesity and early diabetes signs. The group eating higher protein (about 1.4 grams per kilogram of body weight daily) lost more weight, preserved more lean muscle mass, and improved their physical strength and walking ability compared to the standard protein group after six months. This matters because older adults often lose dangerous amounts of muscle when dieting, which can make them weaker and more prone to falls.
Key Statistics
A 2026 randomized controlled trial of 64 older male veterans found that eating higher protein (1.4 grams per kilogram of body weight) during weight loss preserved 0.7 kilograms more muscle mass at 6 months compared to standard protein intake (0.8 grams per kilogram).
In a 2026 pilot study of 64 older men with prediabetes and obesity, those eating enhanced protein showed a 4.7% weight loss at 3 months compared to 3.1% in the standard protein group, while also improving walking distance by 29 meters more in the 6-minute walk test.
A 2026 study of 64 older male veterans found that enhanced protein intake increased hand grip strength by 3.0 kilograms at 6 months compared to 1.2 kilograms in the standard protein group, suggesting better preservation of functional strength during weight loss.
Research from a 2026 randomized controlled trial showed that older men eating 30 grams of high-quality protein four times daily improved their physical function score by 1.5 points at 3 months, compared to 1.2 points for those eating standard protein amounts.
The Quick Take
- What they studied: Whether eating more protein helps older men keep their muscle strength and physical ability while losing weight if they have prediabetes and obesity.
- Who participated: 64 male veterans aged 55 and older with obesity (BMI over 30) and prediabetes. Average age was 67.6 years, and they all had early signs of diabetes.
- Key finding: Men eating higher protein (1.4 grams per kilogram of body weight) preserved significantly more muscle mass and showed better improvements in strength and walking ability compared to men eating standard protein amounts, even though both groups lost weight.
- What it means for you: If you’re an older man trying to lose weight, eating more high-quality protein while exercising may help you stay stronger and keep more muscle. However, this was a small pilot study, so talk to your doctor before making major dietary changes.
The Research Details
This was a randomized controlled trial, which is one of the strongest ways to test if something works. Researchers randomly divided 64 older male veterans into two equal groups. One group ate the standard recommended amount of protein (0.8 grams per kilogram of body weight daily), while the other group ate nearly twice as much protein (1.4 grams per kilogram daily), specifically eating 30 grams of high-quality protein four times per day. Both groups followed a calorie-reduced diet and participated in exercise programs. Researchers measured their results at 3 months and 6 months using standardized tests.
The study measured several important outcomes: physical function using a battery of tests (like how fast they could walk and stand up), muscle mass using a special body composition scanner, body weight, body fat, waist size, walking distance in 6 minutes, how quickly they could stand up and walk, and hand grip strength. All participants started with similar characteristics: average BMI of 35.8, average age of 67.6 years, and early diabetes markers.
This research design is strong because randomly assigning people to groups helps ensure the groups are similar at the start, making it easier to tell if the protein difference caused the results. However, this was a pilot study, meaning it was smaller and designed to test whether the idea was worth studying more thoroughly.
This study design matters because older adults often lose dangerous amounts of muscle when dieting, which can lead to weakness, falls, and loss of independence. Most weight loss studies focus on younger people or don’t specifically track muscle loss. By testing whether higher protein intake prevents muscle loss during weight loss in older men with prediabetes, this research addresses a real health problem that affects millions of older adults.
This study has several strengths: it was randomized (reducing bias), it measured actual muscle mass (not just weight), it included multiple physical function tests, and it followed people for six months. However, readers should know this was a pilot study with only 32 people per group, which is relatively small. The study only included male veterans, so results may not apply equally to women or other populations. The study was well-designed but needs confirmation with larger, more diverse groups before making definitive recommendations.
What the Results Show
The enhanced protein group showed significantly better improvements in physical function compared to the standard protein group. On the Short Physical Performance Battery test (which measures strength, balance, and walking ability), the enhanced protein group improved by 1.5 points at 3 months compared to 1.2 points for the standard protein group. At 6 months, this difference was even more pronounced, with the enhanced protein group showing a moderate effect size (Cohen’s d = 0.68), meaning the difference was meaningful and not due to chance.
Muscle preservation was a key finding. After 6 months, the enhanced protein group lost only 0.8 kilograms of muscle mass, while the standard protein group lost 1.5 kilograms—nearly twice as much. This difference was statistically significant and clinically important because preserving muscle helps older adults maintain independence and strength.
Walking ability improved more in the enhanced protein group. In the 6-minute walk test at 3 months, the enhanced protein group walked an average of 63.3 meters farther than their baseline, compared to 34.4 meters for the standard protein group—a difference of about 29 meters. Hand grip strength also improved more in the enhanced protein group, with a 3-kilogram increase at 6 months compared to 1.2 kilograms in the standard protein group.
Weight loss was also greater in the enhanced protein group at 3 months (4.7% of body weight compared to 3.1%), suggesting that higher protein intake may support fat loss while preserving muscle.
The enhanced protein group achieved faster initial weight loss at the 3-month mark, losing about 1.6% more of their body weight than the standard protein group. This suggests that higher protein intake may increase fat loss specifically while protecting muscle. The improvements in hand grip strength persisted through 6 months in the enhanced protein group, indicating sustained benefits for functional strength. The consistent improvements across multiple physical function measures (walking, standing, strength) suggest that the benefits of higher protein intake were comprehensive rather than affecting just one aspect of fitness.
According to Gram Research analysis, this study aligns with existing research showing that protein helps preserve muscle during weight loss, but it’s one of the first to specifically test this in older men with prediabetes. Previous studies have shown that standard protein recommendations (0.8 grams per kilogram) may not be enough to prevent muscle loss in older adults during calorie restriction. This research supports growing evidence that older adults benefit from higher protein intake (1.2-1.6 grams per kilogram) when losing weight, which is higher than traditional recommendations but lower than amounts used in muscle-building studies.
This was a pilot study with only 32 people per group, which is relatively small. The study only included male veterans, so results may not apply equally to women, younger people, or those from different backgrounds. The study lasted only 6 months, so we don’t know if benefits continue longer. The study didn’t track whether participants continued the diet and exercise after the study ended. Participants knew which group they were in (they couldn’t be blinded to protein intake), which could have influenced their effort or results. The study didn’t measure whether the improvements in physical function translated to real-world benefits like reduced fall risk or improved quality of life.
The Bottom Line
For older men with obesity and prediabetes who want to lose weight, eating higher protein (around 1.4 grams per kilogram of body weight, or roughly 30 grams of high-quality protein four times daily) combined with exercise appears to help preserve muscle strength and physical function better than standard protein amounts. This recommendation has moderate confidence based on this pilot study but should be confirmed with larger research. Consult your doctor before significantly increasing protein intake, especially if you have kidney problems. Combine higher protein intake with regular exercise for best results.
This research is most relevant for older men (55+) with obesity and prediabetes who are trying to lose weight and want to maintain strength and independence. It may also apply to older women, though this study didn’t test that. People with kidney disease should not increase protein without medical supervision. Those already eating adequate protein may see smaller benefits. Younger people losing weight may have different protein needs.
Improvements in physical function appeared within 3 months, with greater benefits by 6 months. Muscle preservation benefits were evident at 6 months. Realistic expectations: noticeable strength improvements within 2-3 months if combined with exercise, with continued benefits through 6 months. Long-term benefits beyond 6 months are unknown from this study.
Frequently Asked Questions
How much protein should older men eat when trying to lose weight?
Research suggests older men losing weight benefit from about 1.4 grams of protein per kilogram of body weight daily, or roughly 30 grams of high-quality protein at four meals. This is nearly twice the standard recommendation and helps preserve muscle mass during weight loss.
Does eating more protein help you lose fat instead of muscle?
A 2026 study of 64 older men found that higher protein intake during weight loss resulted in greater fat loss (4.7% versus 3.1% at 3 months) while preserving significantly more muscle mass, suggesting protein helps your body burn fat preferentially.
Can older adults improve their strength while losing weight?
Yes, according to research reviewed by Gram, older men eating higher protein while exercising and losing weight improved hand grip strength by 3.0 kilograms at 6 months and walked significantly farther, showing that strength gains are possible during weight loss.
What’s the best way to eat more protein as an older adult?
The study showed benefits from eating 30 grams of high-quality protein (chicken, fish, eggs, Greek yogurt, beans) at four separate meals throughout the day, rather than getting all protein at one meal. This approach may help your body use protein more effectively.
How long does it take to see improvements from higher protein intake?
A 2026 pilot study found that older men showed improvements in physical function and walking ability within 3 months of eating higher protein while exercising, with greater benefits by 6 months.
Want to Apply This Research?
- Track daily protein intake in grams and log it against your body weight target (aim for 1.4 grams per kilogram). For example, a 100-kilogram person would target 140 grams daily. Set reminders for four protein-rich meals spaced throughout the day.
- Set a specific goal like ’eat 30 grams of protein at breakfast, lunch, dinner, and snack time’ rather than vague ’eat more protein’ goals. Use the app to log protein sources (chicken, fish, eggs, Greek yogurt, beans) and track which meals hit your 30-gram targets.
- Weekly: track average daily protein intake and compare to your target. Monthly: log physical function improvements (how many stairs you can climb, walking distance, or grip strength if you have access to testing). Every 3 months: reassess weight loss and muscle preservation by taking body measurements and noting strength improvements.
This research is a pilot study with a small sample size of male veterans and should not replace personalized medical advice. Before significantly increasing protein intake or starting a weight loss program, consult your healthcare provider, especially if you have kidney disease, diabetes, or other chronic conditions. Results may not apply equally to women or other populations. This study lasted 6 months, so long-term effects are unknown. Individual results vary based on genetics, overall diet quality, exercise adherence, and other health factors.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.
