As an ER doctor for 20 years, Poonam Desai studied and incorporated daily practices for a long life well before it became her main focus. In 2017, she officially started practicing longevity medicine, helping her patients learn the tools they would need to build a routine that promotes living long and staying healthy.

When it comes to her own health and wellness, Desai, who is also a doctor of osteopathic medicine, follows the routines she typically suggests to her patients. From exercise and social connection to eating healthy foods and prioritizing sleep, "every thing I'm doing, I want to optimize it," she says.

Here are Desai's daily habits for a long, healthy life.

This interview has been edited and condensed for clarity.

'Sleep is my number one thing for longevity'

CNBC Make It: What are some of the practices you do to keep your body healthy?

I really think that number one is sleep. It's something we do every single day. It's free. You have an opportunity to optimize it every single day. So I think sleep is my number one thing for longevity.

What I do particularly for sleep is making sure I go to bed around the same time almost every single day. People don't know that's probably one of the most important things you can do to help you develop a healthy circadian rhythm.

The next important thing is making sure that you expose yourself to sunlight, particularly before 10 a.m., and really decrease the amount of blue light in the evenings. One thing that I implemented in my bedroom is I took out all types of bright light, and I installed lamps that have red light. That really helps set the tone, and tells my body it's time to go to bed.

For exercise I've been using a weighted vest. Every time I go for a walk, I want to optimize that walk, because I don't have much time. I speed walk to increase my heart rate. I'm also strength-training by putting that weighted vest on, which is especially necessary because I am a mother and currently breastfeeding.

When you're breastfeeding and when you're postpartum, you actually may have about up to 20% of bone loss. I'm a woman in her early 40s. At least three times a week I do strength training to help me build my muscle.

I see a lot about brain health and how important it is for longevity. Are there any things you're doing specifically for your brain?

Sleep is number one and number two is nutrition. Just avoiding ultra-processed foods, avoiding additives, avoiding things that could be causing inflammation, is really important.

You really want to optimize things like leafy green vegetables, nuts, protein and omega-3s in your diet. One trick that I absolutely love and tell all my patients is to put chia seeds in your water. That's a great way to get a omega-3s, protein and even hydration. All of that is super important for your brain.

Another really important thing for brain health — that is not spoken about as often as it should — is the importance of connections. So I make sure that I do at least one or two things for social connection every single day.

You never want to go an entire day and not have a deep conversation with somebody, and that could be a friend, a loved one. Not everything should be so regimented, but that conversation that brings you joy and life and helps you feel connected is really important for brain health.

That actually leads directly to my next question. What's your social fitness like?

Oh gosh! Okay, so I'm a mom. I have a lot of interactions just by going to my daughter's school to pick her up. But I also always have a deep interaction with one friend every single day.

It could be literally calling my best friend from high school on my way to pick up my daughter or going for a walk. It could also be calling my aunt, my cousin, my grandma. It's as simple as that.

Sometimes the people may not live in close proximity, so a lot of my interactions — especially because I'm a working mom — happen over the phone. But I make sure to have one call a day with somebody that is close to me. It makes me feel connected.

That's really great advice. I also wanted to know what your daily diet is like. What are some of the foods you aim to eat daily or weekly?

I always start with fiber. Every single day I try to get at least 30 to 40 grams of fiber in my diet. Fiber comes from vegetables, legumes, fruits, whole grains, and nuts — lots of fruits and vegetables.

One of my favorite ways to get fiber into my diet is to put a tablespoon of chia seeds in 30 ounces of water. I have a huge bowl of different fruits almost daily. It could be apples, oranges, kiwi, berries, blueberries, strawberries. I pair that with a lot of raw vegetables like raw cauliflower, raw broccoli and cabbage.

I try to do one serving of either lentils or beans per day. I'm vegetarian, so for me, I also can get fiber from the food I'm eating for protein as well. Second, is healthy fat, so omega-3s. I use olive oil a lot in my cooking, and eat things like avocados, nuts. I try to have at least one serving of those a day.

Then the third, protein. As a vegetarian, my protein usually comes from things like lentils, tofu, beans, legumes and eggs.

For longevity and diet, I am a big proponent of making sure we diversify our foods. I, particularly for me and my children, aim to have 60 different plant foods a week, and these plant foods could be fruits and vegetables, but don't forget about the nuts and the spices. If I'm making eggs, I'm throwing in rosemary or thyme or oregano, turmeric, black pepper. I really optimize the spices.

I'm really cautious about what I'm putting into my body, so I read every single label. If I'm going to have a cookie or a cupcake or ice cream, I make sure that I have fiber, protein or a healthy fat before to curb that glucose spike.

When it comes to drinks, water is always the best, but I kind of spice up all my drinks as well. I don't drink alcohol, but I make my drinks a little fun.

I'll have a matcha latte with oat milk. Another drink I love having, and I call it my immunity booster, has turmeric. I actually take the turmeric root and put it in there. It also has black pepper, ginger and lemon.

This next one is just for fun. What are you currently reading?

I read a lot of research and blog articles that pertain to longevity. Most of what I'm reading is about nutrition, wellness, hormones and longevity.

I even like to look at trending blog posts or trending Instagram Reels and LinkedIn articles. It's really important to know what everybody else is talking about.

The daily practices of a longevity medicine doctor

These are Desai's daily habits:

• For her body: Prioritizing good quality and quantity of sleep, taking walks with a weighted vest and strength training three times a week.
• For brain health: Avoiding ultra-processed foods and eating a plant-based diet filled with omega-3s.
• For social fitness: Having a deep, meaningful interaction with at least one close friend or family member a day.
• For her daily diet: Following a vegetarian diet with a diverse mix of fruits, vegetables, healthy fats, plant-based proteins and spices.
• For her media diet: Catching up on the latest longevity news through articles and social media.

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