Dr. Mariana Calleja Ross on the simple practice for better health.

It makes sense that we all have unique nutritional needs. A person training for a marathon will need to eat differently than someone who only takes strolls. Plus, our physiology and biology vary. But how do you know what diet best fits your needs?

We posed this question to Dr. Mariana Calleja Ross. A physician trained in palliative care, Dr. Mariana is the author and founder behind one of our favorite Substacks,The Feel Good Life, which offers in-depth and hopeful insight into preventive medicine, healing, emotional care, and nutrition.

Every week, Dr. Mariana provides accessible and much-needed wellness tips. Given her focus on eating well and taking a holistic approach to care, we asked her to give us the 101 on what it means to lean into a diet that fits our individual lifestyles.

"Your body produces energy from everything that you consume," she tells us over Zoom. "So, we need hydration, we need sleep, we need movement—but to sustain all those processes, we need food, but we need the right food to give us the right vitamins, the right supplements, and everything we need."

Dr. Mariana gets us started below, offering us one of the most accessible and life-changing tools for caring for ourselves. And if you're curious to learn more, be sure to Subscribe to her newsletter, The Feel Good Life.

A Conversation with Mariana Calleja Ross, MD

Let's start with the big picture: What does it mean to find a diet that fits our needs?

Basically, when I speak about the right nutrition, I speak about the correlation between a person's activities and their regular food intake. We are all different, and even though the human body works all the same, we all have unique needs and requirements depending on a vast array of circumstances, for example, sports level, medical conditions, chronic medications, weather, hydration, genetics—just to mention the most common ones. Nutrition needs to go hand in hand with our daily lives and activities.

But the problem is that most people are running on auto mode, eating what they can when they can, missing a huge window on nutritious food that can actually be used by your body. The consequences of this can be many, from hormone imbalance or digestive issues to dehydration or malnutrition. Since the body is incredibly smart and resilient, it finds ways to adapt to what we give it... But the question here then becomes: for how long? For how long can it adapt, and at what cost? Good nutrition is essential to the body's proper functioning, all the way down to the cellular level. The key factor here is self-awareness. When you start observing and realizing how your body feels on a regular basis, you understand what your body is asking for. A little awareness goes a long way.

How can we start to become more aware?

I would say the first step is simply an act of observation. As I mentioned, when you start paying attention to what your body does regarding sensations, it becomes easier to understand what it is trying to tell you. It becomes easier to catch any possible symptoms here and there or simply to witness how your body functions on a normal basis. When you learn how your body feels and works under average normal conditions, you will then know when something might be a bit out of whack. To do this, I always recommend journaling. A long while back, I created a "Feel Good Journal" that I give to my patients. It's a daily habit tracker including the most important ones that we perform every day, such as eating, sleeping, peeking, pooping, drinking water, and moving. When you start observing and writing down what you did and ate on an average day, you'll be amazed—even after a week or two—to see the patterns that your body is showing you, right in front of your nose.

How have you seen journaling help your patients?

This art of health journaling, as I like to call it, has been a magic life-changer in my patients' lives. They have learned to recognize how stressed they were, how little they were sleeping, how anxious or calm they were feeling, how sugar cravings increased after a stressful day, and how lack of focus and mood swings would increase after a bad night's sleep. Journaling might sound a bit tedious, but trust me, investing two weeks of your time to journal and observe your mind and body will add years to your life.

After learning to recognize your own patterns, it will be easier to sit down and carve a meal plan that suits your needs. Say, for example, you learned that your chronic constipation improves when you drink more water and eat more fiber. You start taking care of this as days go by when suddenly you're managing to poop more regularly and without much struggle.

““When you start observing and realizing how your body feels on a regular basis, you understand what your body is asking for.””

— Mariana Calleja Ross, MD

A perfect example to make it more obvious is when people are diagnosed with diabetes. As soon as blood sugar medication begins, a person learns to eat differently, observing carefully what happens when they eat certain foods and how the body reacts. Ideally, we don't want to reach such a level, but it's a good way to show how observation and improving habits can really shift your health around if you put in the effort.

When we starting this process, are there foods or habits we should avoid?

Any excess of processed sugars and carbs isn't great for your health. We know that the body needs energy to function, but an excess of processed foods can be detrimental to the actual energetic production and consumption process in your cells. We also have proof of sugar being addictive. This happens because of different biological processes in several organs that control vital functions. Organs like the pancreas, the liver, and the brain can all be highly affected by large consumption of these kinds of foods. It all connects. Hence why, awareness is everything. I will keep saying this for as long as I live!

Lastly, regarding good nutrition and overall health, what is one habit everyone could adopt today to make a difference?

Schedules! You know how adults make sure that kids have a regular bedtime, mealtimes, playtimes, and proper sleep? Well, the fact that we grow up into adults doesn't mean we stop needing such routines. As adults, we fail to stick to regular schedules many times due to work, rush hour, family or professional commitments, and so on. But in reality, when we lose track of how many hours we sleep or at what times of the day we eat, both brain and body suffer, bringing all sorts of health consequences, starting with insomnia, anxiety, high blood pressure, high cholesterol, dysregulated thyroid or menstrual periods, just to mention a few.

So, I confidently say that the one habit to adopt to make a difference, whether for the sake of nutrition, cardiovascular health, or overall health, is to try to set up healthier routines: a regular bedtime and wake-up time, similar eating times every day as possible, drinking enough water every day (some foods, fruits, and teas count!). I always advise my patients to think of their brains as toddlers. If it's tired, it'll get cranky; if it's hungry, it'll get moody; if it's fresh and clear, it'll be in a calm and good mood. And so on. We need to realize that steady routines, as best as possible, will inherently help our entire body to work properly and in balanced ways.

A calm mind and a balanced body will lead to a calm and balanced human. It should go without mentioning that all this impacts the way we address life, including its struggles, tough days, waves, and beyond. When the mind and body are somehow calm, clear, and strong, our ability to navigate difficult times improves. It's not about being perfectly happy and calm 24/7; that's not life. It's about learning enough about yourself, both physically and emotionally, that no matter what comes, you can sail through with the best that you are. And this, to me, is what health is really about.

We’ll have more insight from Dr. Mariana Calleja Ross. In the meantime, be sure to subscribe to her newsletter,The Feel Good Life, for more health, nutrition, and holistic living tips!