As we journey through life, the inevitability of ageing becomes apparent, yet many of us desire to maintain a youthful appearance and spirit.
While we may not have access to a mythical fountain of youth, Dr. Ian K. Smith offers practical advice in his latest book, Eat Your Age, on how to combat the effects of ageing.
Dr. Smith, a Harvard-educated physician, emphasizes that youthful vitality is not solely reliant on financial resources or surgical interventions. “It’s about planning, being attuned to your body and health, and implementing straightforward steps to cultivate a life filled with energy and vibrancy, regardless of how many candles light up your birthday cake,” he states.
His book is grounded in the understanding that our nutritional, metabolic, and medical requirements change as we age, which necessitates a corresponding evolution in our eating habits.
Rather than prescribing a universal diet, Dr. Smith guides readers on how to tailor their food choices, physical activity, and preventive care to the unique demands of each decade of life.
“The aim is to decelerate metabolic decline, maintain muscle mass, lower chronic disease risks, and extend health span—not just lifespan,” he explains. “This framework empowers individuals to take charge of their ageing process through science-backed strategies, making longevity a purposeful and attainable journey.”
Below, Dr. Smith outlines essential dietary, exercise, and health measures for each decade to help individuals look and feel rejuvenated.
In your 30s
Your choices in your 30s lay the groundwork for future ageing, according to Dr. Smith. “Though the body remains resilient, early metabolic changes are starting, making proactive strategies more impactful than reactive ones,” he says.
This decade is crucial for establishing solid nutritional habits, consistent physical activity, and medical awareness, which will yield benefits for years to come.
> Eating for Prevention
Dr. Smith advises shifting focus from merely counting calories to prioritizing nutrient density, emphasizing lean proteins, fiber-rich vegetables, and healthy fats, while cutting down on ultra-processed foods. “This decade is about preventing insulin resistance before it sets in,” he notes.
Your metabolism remains relatively robust, but subtle shifts can start to occur. Blood sugar management, cholesterol levels, and inflammation markers can drift off course without obvious signs.
“Thus, the emphasis should be on eating for prevention, not correction,” he emphasizes. “Balanced meals with protein, fiber, and healthy fats slow digestion, lessen blood sugar spikes, and promote sustained energy throughout the day.”
He cautions that while skipping meals or leaning heavily on refined carbohydrates might not cause immediate weight gain, it can lead to metabolic issues down the line.
> Set Consistent Exercise Goals
Establish a regular strength training routine (aim for at least two to three days each week).
“Building muscle mass in your 30s acts as metabolic insurance for later in life,” Dr. Smith explains. “Strength training enhances insulin sensitivity, safeguards your joints, and elevates your resting metabolic rate.”
Pair strength training with moderate cardiovascular activities, such as brisk walking, cycling, or swimming, to ensure heart health without overexertion.
> Medical Screening
Consider baseline lab tests like fasting glucose, lipid panels, blood pressure measurements, and waist circumference.
“These indicators create a personal health benchmark and enable early detection of silent risks,” he adds.
In your 40s
The 40s signify a transition from building health to actively safeguarding it, Dr. Smith notes. Hormonal fluctuations and gradual metabolic slowdowns mean the body doesn’t react the same way it used to, even if your habits stay constant.
“This decade demands smarter nutrition, intentional exercise, and proactive screenings to stay ahead of potential health issues,” he emphasizes.
> Nutrition to Support Hormonal Shifts
As metabolic rates decline, adequate protein intake becomes crucial for maintaining lean muscle mass and appetite control.
Changes in hormones, especially estrogen, testosterone, and cortisol, begin to affect fat storage and stress response. “It’s vital to distribute protein evenly across meals rather than saving it all for dinner,” Dr. Smith cautions. “This promotes muscle repair, stabilizes blood sugar, and curbs late-night overeating.”
Additionally, paying attention to portion sizes and minimizing liquid calories becomes increasingly essential, as caloric needs tend to drop even if hunger persists.
> Maintain Cardiovascular Fitness
Incorporate higher-intensity workouts alongside strength training, including short bursts of interval training to preserve cardiovascular fitness and counteract age-related metabolic slowdown. “Recovery is paramount during this decade,” he advises. “Adequate sleep, mobility work, and rest days are crucial to avoid burnout and injury.”
> Medical Screening
Initiate discussions about routine bowel cancer screenings, alongside regular monitoring of blood pressure, cholesterol, and diabetes, especially if there’s a family history of these conditions.
In your 50s
As you enter your 50s, health becomes less about weight and more about resilience, according to Dr. Smith. “Muscle loss, inflammation, and chronic disease risks increase if not actively managed through diet and exercise,” he warns. “The focus during this decade should be on preserving strength, protecting joints, and maintaining metabolic balance.”
> Focus on Healthy Fats and Diverse Foods
Embrace an anti-inflammatory diet that includes omega-3 fats, colorful vegetables, whole grains, and reduced added sugars, he suggests. As digestive efficiency and insulin sensitivity decline in the 50s, food quality becomes more critical than quantity. “Inflammation—not ageing itself—is a key driver of chronic disease,” he notes. Foods rich in antioxidants play a protective role for blood vessels, joints, and the brain.
While sufficient protein intake remains vital, staying hydrated is equally important as thirst senses can diminish with age. Mindful eating and pacing your meals can also enhance digestion and nutrient assimilation.
> Mobility and Strength Training
Make strength training an essential part of your routine, alongside exercises that improve balance, flexibility, and stability, such as single-leg movements. “Muscle loss can accelerate during this decade if not proactively countered,” he warns.
> Medical Screening
Schedule bone density tests and screenings for cardiovascular disease, diabetes, and certain cancers. “Early detection significantly enhances outcomes,” he stresses.
Your 60s and Beyond
In your 60s and beyond, the emphasis shifts from optimization to the preservation and targeted growth, Dr. Smith observes. “Daily habits now dictate mobility, cognitive function, and independence more than the numbers on a scale,” he points out. “Prioritizing nutritious food, consistent movement, and medical vigilance lays the groundwork for a longer, healthier life.”
> Specific Nutrient Needs
Focus on adequate protein, calcium, vitamin D, and hydration, while moderating total calorie intake. “Appetite might decline, yet nutrient requirements remain high,” he notes, warning that under-consuming protein is a frequent and dangerous mistake among older adults. “Protein supports muscle strength, immune health, and recovery from illness, and meals should be nutrient-dense, straightforward, and easy to digest,” he explains.
> Stay Mobile to Minimize Fall Risk
Emphasize functional movement—strength, balance, flexibility, and walking. “The aim is not intensity, but consistency and safety,” Dr. Smith advises. “Regular movement enhances mobility, decreases fall risk, and supports brain health. Even short daily sessions can create a significant impact.”
> Medical Screening
Continue with consistent vision, hearing, cognitive, cardiovascular assessments, and medication reviews. “These evaluations preserve quality of life and support independence well into later years,” concludes Dr. Smith.
