Hydrate and Thrive: Why Water Is the Most Important Nutrient, and How You Can Get Enough

February 18, 2026
Summary
Webinar Q&A

View the Webinar Recording

Summary

In This Webinar

  • Functions of water in the body
  • Benefits of water
  • Daily fluid requirements
  • Best fluids for hydration
  • How to increase daily fluids
  • Your action plan for fluids

Roles and Benefits of Water

Water is the most critical nutrient. Humans can survive for more than 3 weeks without food, but only 3-4 days without water. You need water for:

  • Metabolism
  • Thermal control
  • Immune function
  • Blood volume
  • Joint cushioning
  • Cognitive function

You lose water through: 

  • Sweat
  • Skin
  • Respiration
  • Waste

The body is 60% water!  You can only survive for 3-4 days without water.

Water may help protect against the following. 

  • Certain cancers
  • Heart health
  • Kidney disease
  • Kidney stones
  • Blood sugar, diabetes risk
  • Urinary tract infections
  • Lower mortality rates!

Chronic mild dehydration can raise risk for weight gain and low energy

One Way That Water Works - Angiotension II Example

Angiotensin II is an enzyme in your body that works to raise blood pressure. Here’s what happens when you’re mildly dehydrated.

Blood volume decreases, which makes blood pressure decrease.

Your body releases more angiotensin II to try to increase blood pressure. 

Angiotensin II causes:

  • Thirst (so you seek water)
  • A drive for sodium (such as salty foods)
  • Vasoconstriction (blood vessels narrow)
  • Water conservation (less sweat and urine production)

Chronic mild dehydration can lead to a higher risk for: 

  • High blood pressure due to higher levels of angiotensin II
  • Obesity due to a frequent drive for salty foods, such as chips, pretzels, nachos, and fast food
  • Diabetes, due to higher blood glucose concentrations and frequent need to use more insulin to lower blood sugar

When you stay hydrated, you’re helping prevent a rise in angiotensin II and these effects!

Daily Requirements for Hydrating Fluids

How much fluid do you need per day? 

Category Daily Adequate Intake (AI) From Beverages (Approx.) When Needs Increase
Women 2.7 Liters (91 oz) 73 oz
  • Illness (Fever/Vomiting)
  • Hot & Humid climates
  • Exercise / Sweating
  • High Physical Activity
Men 3.7 Liters (125 oz) 100 oz
General Target 64–96 ounces per day Note: ~20% of fluids come from food.

64-96 ounces looks like:

64–96 Ounces Per Day Looks Like...
The Large Container ½ to ¾ Gallon
Standard Bottles 2 to 3 (1-Liter) bottles
Individual Bottles 4 to 6 (16.9 oz) bottles
Standard Servings 8 to 12 (8 oz) cups

.

Low-Calorie Beverages for Daily Fluid Consumption

Plain water or ice water is the gold standard! Unsweetened sparkling water is also great. Try infused water, such as with lemon, lime, herbs, ginger, peach, strawberries, or another fruit. Decaffeinated black coffee or unsweetened tea are low in calories. Low-sodium broth is a savory option.

Some Caloric Beverages Can Add Nutrients

Some beverages have calories, but can add important nutrients. Choose these mindfully and watch portions. 

Beverage Choice Nutritional Boost Calories (per 8 oz)
Fruit Juice Vitamin C, Folate 120
Skim / Unsweetened Soy Milk Protein, Calcium 90
Vegetable or Tomato Juice Vitamin C, Potassium 40
Unsweetened Almond Milk Calcium 40

These can be high in calories, carbohydrates, and sugar. They can contribute to tooth decay and interfere with weight management goals. Here are examples. 

  • Sweetened or flavored coffee 
  • Sweet tea or boba tea
  • Soft drinks
  • Sports drinks
  • Energy drinks
  • Juice drinks, lemonade, fruit punch
  • Mixed alcoholic drinks

What About Milk and Coffee?

Milk can be high in calories compared to lower-calorie beverages, but it has important nutrients, including protein and calcium. Studies suggest that it may be neutral or have a positive effect on weight and chronic conditions. 

Coffee has antioxidants and caffeine. Caffeine has some health benefits in moderation, but too much caffeine can be not only risky for physical and mental health, but also dehydrating due to its laxative and diuretic effects. The general recommendation is to stay under 400 mg of caffeine per day (4 small cups of coffee), but ask your healthcare provider for specific recommendations for yourself. 

Ways to Get More Fluids

Here are some strategies for getting more fluids. 

  • Log/track it (app, notebook, refrigerator)
  • Use a timer or app for reminders or notifications
  • Tie drinking water to other actions, like eating meals and snacks or going to the bathroom
  • Set out goal amount at beginning of day and finish it by end
  • Drink better-tasting drinks or a variety of fluids to make it more interesting

Create Your Hydration Plan

Download your printable worksheet here! www.lark.com/resources/lark-hydration-worksheet

Your New Hydration Plan Step 1: Name Your Goal: For example, my goal is…

  • To drink 72 ounces of hydrating fluids per day
  • To drink an extra 8 ounces of water before breakfast and before lunch

Set a goal that’s only a small amount more than your usual amount to keep it realistic.

Your New Hydration Plan Step 2: Visualize It What does your goal for fluid consumption look like? For example, my goal is…

  • Drink 8 8-ounce cups of water per day. OR
  • Drink 4 16-ounce (half-liter) plastic water bottles. OR
  • Add 4 8-ounce cups of water per day

Think of your goal in terms of something that you can visualize.

Your New Hydration Plan Step 3: Schedule Hydration

When will you drink your fluids? You can use alarms to drink at certain times of the day, or attach beverage consumption meals or snacks. You can also attach your goal to habits that already exist and that you’re sure to do. Examples include going to the bathroom, self-care (take vitamins, wash face, brush teeth), arrive at your destination, turn on the tv or change the channel, check your email, and sending a text message. 

Your New Hydration Plan Step 4: Create Reminders

Put notes where you’ll see them at times that it makes sense to drink! Sticky notes can go on the fridge or laptop screen. Set phone alarms, or place a pitcher of water on the desk or counter. 

Your New Hydration Plan Step 5: Track and Celebrate! Log water as you drink so it’s easy to track. Track with:

  • Water bottles with quantities marked
  • Number of cups, water bottles or pitchers
  • Sticker chart or tally

Celebrate when you hit your goal. For example,

  • Unlock 5 minutes of “you” time.
  • Add a coin to a piggy bank for a treat when it’s full
  • Tell someone

After this webinar…

  1. Track your baseline water and hydrating fluid consumption to get a baseline
  2. Identify a way you can add more water to your daily total
  3. Implement your new hydration plan

References

Dmitrieva NI, Gagarin A, Liu D, Wu CO, Boehm M. Middle-age high normal serum sodium as a risk factor for accelerated biological aging, chronic diseases, and premature mortality. EBioMedicine. 2023 Jan;87:104404. doi: 10.1016/j.ebiom.2022.104404. Epub 2023 Jan 2. PMID: 36599719; PMCID: PMC9873684.

https://pmc.ncbi.nlm.nih.gov/articles/PMC7259248/

Dougkas A, Hobbs D. A Review of the Role of Milk and Dairy Products in the Development of Obesity and Cardiometabolic Disease. Curr Dev Nutr. 2020 May 29;4(Suppl 2):1629. doi: 10.1093/cdn/nzaa063_027. PMCID: PMC7259248.

https://pmc.ncbi.nlm.nih.gov/articles/PMC5563313/

Seal AD, Bardis CN, Gavrieli A, Grigorakis P, Adams JD, Arnaoutis G, Yannakoulia M, Kavouras SA. Coffee with High but Not Low Caffeine Content Augments Fluid and Electrolyte Excretion at Rest. Front Nutr. 2017 Aug 18;4:40. doi: 10.3389/fnut.2017.00040. PMID: 28868290; PMCID: PMC5563313.

MOHAMMAD MEHDI FARSHCHI NASR, AMENEH MADJD, HAMID R. FARSHCHI; 586-P: Effects of Replacing Diet Beverages with Water on Sustained Weight Loss and Type 2 Diabetes Remission—An 18-Month Randomized Clinical Trial. Diabetes 20 June 2025; 74 (Supplement_1): 586–P. https://doi.org/10.2337/db25-586-P

Bracamontes-Castelo G, Bacardí-Gascón M, Jiménez Cruz A. Effect of water consumption on weight loss: a systematic review. Nutr Hosp. 2019 Dec 26;36(6):1424-1429. English. doi: 10.20960/nh.02746. PMID: 31657610.

https://pubmed.ncbi.nlm.nih.gov/31657610/

Jeong JN. Effect of Pre-meal Water Consumption on Energy Intake and Satiety in Non-obese Young Adults. Clin Nutr Res. 2018 Oct;7(4):291-296. doi: 10.7762/cnr.2018.7.4.291. Epub 2018 Oct 31. PMID: 30406058; PMCID: PMC6209729.

https://pmc.ncbi.nlm.nih.gov/articles/PMC6209729/

Health Coach Q & A

What links should I know about? 

Lark is here to help!

Lark Customer Support!

https://support.lark.com/hc/en-us/requests/new

Hydration Worksheet

www.lark.com/resources/lark-hydration-worksheet  

Facebook page for DPP

https://www.facebook.com/groups/larkdpp

Lark blog

https://www.lark.com/blog

Lark recipes

https://www.lark.com/resource-type/recipe

Email a Lark coach with questions or to make an appointment

coaching@lark.com

https://app.acuityscheduling.com/schedule.php?owner=21319234

Is drinking alkaline water (pH water) actually making a difference in our health? 

Probably not. While alkaline water (or pH water) is safe to drink, your body is already an expert at balancing its own pH if you’re a healthy individual. When you drink alkaline (low-acid) water, your stomach neutralizes it in a high-acid environment. Within your body, your pH (acidity/alkalinity) stays within a tightly regulated, narrow range. 

If you enjoy the taste and it helps you drink more water, go for it! But from a weight loss and blood sugar perspective, plain water does the job just as well. If you want to alkalinize your diet, eating more fruits and vegetables may do a better job in terms of long-term health benefits for bones, though research is ongoing. 

What about coconut water?

Coconut water has electrolytes like potassium, magnesium, and sodium. It can be slightly better for rehydration after heavy sweating, though most people don’t work out intensely enough to require it. 

Coconut water has 45–60 calories per 8 oz and about 6–10 grams of sugar. Drinking coconut water for a major source of hydration can interfere with weight loss due to calories adding up. 

The sugar is natural, but your body uses it the same way that it does with added sugar. Plus, since coconut water is a liquid, the sugar gets absorbed quickly, so your blood sugar can spike. 

Is there a difference in drinking tap water and drinking sparkling water like Bubly?

For hydration and calories, there’s no difference. Both hydrate, and both are calorie-free and sweetener-free. 

Sparkling water can make you feel more full due to the carbonation. It can also have the advantage of swapping for sodas and diet sodas if you’re used to drinking them. However, some people find they get bloating or gas with carbonated beverages. 

What are your thoughts on hydrogen water?

Hydrogen water is essentially water meant to fight inflammation. Scientifics studies are ongoing and fascinating, especially for athletes looking to recovery faster. However, it’s quite expensive and the gas (the super charge) escapes quickly after you open the bottle. 

I just learned that in order to know how much water to take I have to divide my weight by 2 and the answer is the result of the oz. Is this true?

That’s a great question! This formula can give you an estimate, though it’s just an estimate. If you weigh 200 lb, for example, your formula would yield 100 ounces per day. That’s a good amount for someone who is active, trying to lose weight, and already drinks plenty of water. It’s important to go by how you feel and what your healthcare provider suggests. 

Club soda or seltzer?  which is better?

Club soda is unflavored sparkling water. Seltzer water is unflavored sparkling water with some minerals added back in for flavor. Seltzer water has about 50-90 mg sodium per serving. If you’re watching your sodium intake, be sure to count that sodium among your sources. 

Hint- is that low cal?

Great news - Hint is calorie-free! It’s also free from sugar and sweeteners, so it can be a great hydration choice!

What about N/A beer?

Non-alcoholic beer is a healthier choice than alcoholic beer. It has no alcohol, so there’s less of an effect on blood sugar, not to mention mental impairment and the risk for accidents. It is made with grains, so it does have calories and carbohydrates. 

It’s lower in calories than alcoholic beer, with 40-90 calories per 12-ounce can compared to 150-220 per 12-ounce can. Swapping non-alcoholic beer for regular alcoholic beers can save calories and support weight management and blood sugar control. However, drinking any beer - alcoholic or not - adds calories. 

What about a small latte?

That sounds like a really good choice. It can be a nice, warming treat that’s a bit creamy with the milk, but has no added sugars if you don’t add sugar or syrup. 

What about matcha?

Matcha can be a good choice for hydration for many people, depending on how it’s prepared and how sensitive you are to caffeine. Matcha powder that you prepare in hot water is low in calories, with about 5 per serving. 

Matcha has about 25% the amount of caffeine as in coffee, so most healthy people can safely have matcha. 

There are many matcha beverages that are high in calories and sugars. Some powdered products in supermarkets are mixed with sugar or powdered milk and are higher in calories. Cafes may also serve matcha drinks with additives like sugar or syrup. 

How do one know how much water he/she must drink in a day? 

Water requirements are individual. You might consider looking at the Adequate Intake (AI) of 15 cups for men and 11 cups for women and seeing how you compare. If you’re far from that, consider increasing your intake gradually. 

You can also ask your provider how much to drink each day. People who are trying to lose weight, active individuals, and people who sweat a lot are examples of people who may need more liquids each day. It’s an individual question. 

Should we drink water when we aren't thirsty to meet the water intake goals? And, Should we be drinking water when we aren't thirsty? I might not get enough because I don't feel thirsty.

Good questions. The body’s thirst mechanism is a little bit delayed. That means that by the time you feel thirsty, you’ve already lost some water. It’s best to use thirst as a guide when needed, but to try to prevent thirst when possible. 

The thirst mechanism weakens with age - older adults have more difficulty feeling thirst. In addition, if you’ve gone for years without listening to your body’s thirst signals or you’re chronically mildly dehydrated, you may not feel thirst as soon or as sharply. 

It’s a good idea to check your urine color. If it’s brown, you may be dehydrated. 

Try comparing your intake to the AI. If you’re below it, it’s a good idea to add some water daily and see how it goes.

I always heard that if you drink water during your meal it interferes with digestion. Is that true?

Good news - no, it’s not true! Water aids digestion. It helps your stomach produce acid, which is necessary for digestion. It helps your food break down to release nutrients. It helps the digesting food stay at the right consistency to move along. It helps with fiber management, too.  

Water also helps you pace yourself to avoid overeating - if you find yourself eating too fast, use a glass of water as a built-in 'speed bump' for your meal by taking a sip between bites. 

Some people, like those with gastrointestinal reflux disease (GERD) or people who have had bariatric surgery, may need to follow strict rules about how much or whether to drink fluids with meals. Ask your healthcare provider!

Are there any negative impacts of drinking more water than normal? And, I have heard you can drink too much water?  Is this true?

It is true that you can over hydrate! It’s called hyponatremia. It happens when you drink so much water so fast that you wash out your body's essential salts. To stay safe, never 'chug' massive amounts at once, like doing a drinking challenge. 

Keep in mind that your kidneys can safely process about 4 cups per hour. 

Your goal is steady sipping. If you're exercising intensely for over an hour, consider adding electrolytes to your water rather than just drinking it plain. 

Where on Lark do you track water intake?

Great question! When you log, you can be motivated, informed, and more likely to reach your goals! You can log water and any beverage on Lark when you log your food intake. It’s all in one place!

OUR next live webinar

Your Body, Your Kitchen, Your Rules: Balanced Meal Planning and Recipes for Everyone

March 4, 2026 12:30 PM
Members of Lark's Diabetes Prevention Program can check your emails for registration information! Not a member? See if you're eligible for live webinar access and more.