Can You Live Longer with "45-25-10"? Decoding the German Diet Method for Japanese Tables

For health, should we reduce carbohydrates or increase protein?

The more you research diets, the more you encounter seemingly contradictory advice. Enter the numbers "45-25-10" introduced by Germany's FOCUS online.

An article dated October 11, 2026, introduces eating habits for healthy aging from a book by biologist and author Nina Ruge. The core idea is to incorporate more plant-based foods, choose quality fats, and ensure fiber intake.

However, before interpreting "following this ratio will lead to longevity," there are points to confirm. The original article is an excerpt from a book, not a report of new clinical trials. Not all the introduced figures and advice are the optimal solution for Japanese people.

"45-25-10" Does Not Add Up to 100

The original article indicates the following proportions of daily energy intake:

• Carbohydrates: 45-60%
• Fats: 25-30%
• Protein: 10-20%

In other words, "45-25-10" represents the lower limits of each range and is not a fixed distribution. In reality, 45+25+10 only adds up to 80%.

Also, this is not the proportion of food weight or plate area. It does not mean "45% of the plate should be vegetables," but rather the ratio of energy derived from nutrients.

In Japan's "Dietary Reference Intakes (2025 edition)," the target for ages 18-49 is carbohydrates 50-65%, fats 20-30%, and protein 13-20%. There are overlapping parts, but they do not completely match.

Rather than memorizing numbers, it might be more practical in daily life to ensure the necessary amount of food and then look at the combination of staple foods, main dishes, and side dishes.

Instead of Making Rice the Enemy, Change the "Content" of Carbohydrates

What stands out in the original article is that carbohydrates are not uniformly eliminated.

On the other hand, it strongly recommends vegetables and advises moderation with whole grains, which need not be generalized. The WHO lists whole grains, vegetables, fruits, and legumes as primary carbohydrate sources.

In Japanese meals, there are options other than completely removing rice. Replace part of the white rice with barley or brown rice. Add small dishes of tofu or vegetables to a lunch that tends to consist only of noodles. Replace sweet drinks with unsweetened tea.

Even among "foods containing carbohydrates," the nutrients consumed differ between soft drinks and barley rice, or sweets and legumes.

When considering longevity diets, it is helpful to choose foods not just based on the carbohydrate category but also considering fiber and other factors.

Before Adding "Healthy-Looking Oils," Consider Replacements

The original article recommends olive oil, canola oil, nuts, and fish.

Regarding fats, it is important to look at both the amount and the type. The WHO also advocates prioritizing unsaturated fatty acids found in fish, nuts, and vegetable oils over fats high in saturated fatty acids.

However, even olive oil and nuts contain energy. Adding them in large quantities without changing your usual diet can lead to overeating.

Replace part of the butter used in cooking with vegetable oil. If you've been eating meat dishes consecutively, make the next meal fish or tofu. Replace part of your snacks with a small amount of unsalted nuts.

Instead of thinking "adding good oil is reassuring," it is easier to practice by deciding what to replace in your usual diet.

Do Not Reduce Protein Regardless of Age

The amount of protein is something to read carefully in the original article.

The article suggests as a general guideline 0.7-0.8g per kg of body weight per day, with a need for more after ages 60-65. For someone weighing 60kg, this equates to 42-48g.

However, this value should not be considered the "correct answer for longevity" applicable to everyone.

In Japan's dietary reference intakes, the lower limit for protein for those aged 65 and over is set at 15% of total energy, considering frailty prevention. As age increases, maintaining muscle strength and physical function becomes essential.

Increasing plant-based foods and reducing protein itself are separate matters. There are ways to incorporate natto, tofu, and legumes while also combining fish, eggs, and dairy products.

The original article also advises consuming most of the protein in one meal. However, based solely on this introduction, there is no need to remove the main dish from breakfast or lunch.

For those undergoing dietary therapy for kidney disease, it is better to prioritize individual instructions over these general numbers.

Before Aiming for 600g of Vegetables, Start with Japan's "350g"

The original article suggests 600g of vegetables, 200g of fruits, and at least 30g of fiber per day, emphasizing the diversity of plant-based foods by aiming for 25 varieties per week.

The idea of incorporating various ingredients is useful. However, not achieving all of these does not mean you cannot be healthy.

Japan's Health Japan 21 (third edition) sets a goal of an average vegetable intake of 350g and 200g of fruits. This is a national dietary improvement goal and can serve as a reference when considering individual meals.

For those who rarely eat vegetables, start by adding an extra dish to lunch or dinner. If it's hard to secure the amount with raw vegetables alone, use cooked vegetables or stews. If you can't use up purchased vegetables, incorporate frozen vegetables.

Instead of making "25 varieties per week" an obligation, you can start by adding mushrooms or legumes to your usual komatsuna. If counting the types of ingredients becomes a burden, you can slightly change the colors or cooking methods.

Do Not Equate Fruit Sugar with Sugar in Sweet Drinks

The original article mentions that fructose can turn into fat, cautioning against eating large amounts of sweet fruits.

Avoiding overeating is important, but concluding "fruits make you fat, so it's better to avoid them" is premature.

Japan's official information suggests a goal of 200g of fruits per day and recommends eating them raw rather than as juice. The WHO also distinguishes between the fruits themselves and free sugars in fruit juices, which are subject to restriction.

When incorporating this in Japan, there's no need to stock up on special berries. Choose readily available fruits like mandarins, apples, and kiwis in appropriate amounts.

It's better not to treat "drinking a lot of juice instead of eating fruit" and "eating fruit after a meal" as the same habit.

Is "Zero Processed Foods" Necessary for Japanese Living?

The original article also advises eliminating processed foods and avoiding foods with more than seven ingredients.

However, nutrition quality is not determined solely by the presence of processing or the number of ingredients.

Tofu, natto, and unsweetened yogurt are also made through processing. Frozen vegetables and canned goods help reduce cooking burden and food waste. The WHO includes frozen and canned vegetables and fruits as options if they do not contain added sugars or excessive sodium.

Some foods have high salt or sugar content despite having few ingredients. Conversely, foods with various vegetables and beans may have more ingredients.

When shopping, it is more useful to look at the salt equivalent, nutritional content, and the overall positioning in the diet rather than just the number of ingredients.

Choosing meals with frozen vegetables and tofu on busy days does not mean you have "failed at a longevity diet."

Voices of Confusion on SNS About "How to Balance Longevity and Muscle"

The SNS reaction to this FOCUS article itself was not fully grasped within the range that could be confirmed. Here, we introduce past public discussions surrounding longevity diets and protein. These are not direct reactions to the latest article or indicative of overall public opinion trends.

In a 2023 post on the nutrition community of the overseas forum Reddit, it was mentioned that a prominent figure in the longevity field recommends a high-protein diet on one hand while expressing concerns about plant-based diets and high-protein diets on the other, leading to feelings of confusion.

The same thread includes comments urging not to treat explanations of mechanisms occurring within cells as direct evidence of health outcomes in humans.

In another post from 2020, a question was raised about how to balance the goal of longevity with increasing muscle mass and strength.

These discussions suggest that interest in longevity is not only about "how many years one can live" but also about maintaining the ability to walk and be active, which influences food choices.

However, experiences and advice on SNS do not prove the effectiveness of dietary methods. It is necessary to read them in light of one's age, activity level, health condition, and official nutritional guidelines.

For Japanese Tables, Start with These Combinations

If you want to incorporate the ideas from the original article into Japanese living, there are ways to organize your usual meals rather than buying special "longevity foods."

For example, consider the following combinations. These are not therapeutic meals with calculated nutritional values but examples of food choices.

• Breakfast: Barley rice, natto, boiled komatsuna, fruit
• Lunch: Rice, main dish of fish or tofu, vegetable side dish
• Dinner: Staple food, dish using beans or chicken, warm vegetables with mushrooms
• Snacks: Unsweetened yogurt or a small amount of unsalted nuts as needed

Adjust the amount you eat according to your age, activity level, and appetite. Even with Japanese cuisine, soy sauce, miso, and pickles can increase salt content, so pay attention to seasoning.

A diet for healthy aging is not about matching the same numbers every time. It is important to increase vegetables and beans, choose staple foods, and ensure necessary protein in a way that can be sustained in your lifestyle.

Sources and References

1. FOCUS online: Dietary proposals by Nina Ruge.Descriptions regarding "45-25-10," vegetable and fruit quantities, and processed foods.
   https://www.focus.de/gesundheit/longevity/das-ist-der-perfekte-ernaehrungsplan-fuer-ein-langes-leben_0d5faa88-d737-4d88-a786-b21fd2a13958.html

2. Ministry of Health, Labour and Welfare - e-Health Net "Energy-Producing Nutrients": Japan's target ratios for the three major nutrients and securing protein for the elderly.Health Japan 21 Action Support System Website
   https://kennet.mhlw.go.jp/information/information/dictionary/food/ye-013

3. WHO "Healthy diet": International guidelines on the selection of whole grains, legumes, the quality of fats, free sugars in fruit juices, and the use of frozen and canned foods, and salt reduction.who.int
   https://www.who.int/en/news-room/fact-sheets/detail/healthy-diet

4. National Institute of Health and Nutrition "Health Japan 21 (third edition) Target List": Japan's target values of 350g of vegetables and 200g of fruits.nibn.go.jp
   https://www.nibn.go.jp/eiken/kenkounippon21/kenkounippon21/mokuhyou3rd.html

5. Ministry of Health, Labour and Welfare - e-Health Net "Recommendation of 200g of Fruit per Day": The concept of fruit intake and choosing fresh fruit over juice.Health Japan 21 Action Support System Website
   https://kennet.mhlw.go.jp/information/information/food/e-01-003.html

6. Reddit - 2023 Public Discussion: Posts expressing confusion over differing protein advice from figures in the longevity field and comments seeking evidence for health outcomes. Referenced as examples of reactions on SNS, not medical evidence.reddit.com
   https://www.reddit.com/r/ScientificNutrition/comments/14v7phu/peter_attia_v_david_sinclair_on_protein/

7. Reddit - 2020 Public Discussion: Questions about balancing longevity with increasing muscle mass and strength. Not a direct reaction to the current article.reddit.com
   https://www.reddit.com/r/ScientificNutrition/comments/jkbd74/