Hydration and Weight Loss: Can Drinking Water Help You Lose Weight?

Note: This transcript is abridged. For the complete episode, click "play" on the podcast link above.

Dr. Mike: Hey, Dr. Mike here. So, you want to live forever…ish? Then you [have to] know what's in and what's not. Stay tuned to find out.

Live Foreverish Introduction: You're listening to Live Foreverish, a show dedicated to helping you live just a little longer. Here are your hosts, Dr. Mike Smith and Dr. Crystal Gossard.

How Does Drinking Water Support Weight Loss? 00:00:17

Dr. Mike: All right, welcome to Live Foreverish. Dr. Crystal, the in and out. It's that time of the month.

Dr. Crystal: Yes. I love this show.

Dr. Mike: Fantastic stuff. Living Foreverish: there [are] three things you want to do to live a little longer, but a lot stronger.

That's another good way of saying it. I like that.

Dr. Crystal: A little longer and a lot stronger.

Dr. Mike: Three things that you want to do and then something you don't want to do. The out [and] the not—what have you. Let's get right into it.

Number one on the list—this is interesting for me because if you were to read this statement on Google or something without really researching references, you might be like, “Oh, it's a fatty little thing. Whatever. I'm not gonna worry.” But it turns out there's some good research, and that is, water [is good] for weight loss.

Dr. Crystal: Yes. And when you think about it, it makes sense. It's a tricky way to get people to consume more water. I definitely upped mine.

Dr. Mike: A tricky way.

Dr. Crystal: Once I saw this, I said, “Oh, there it is. That's more motivation to meet my water requirements.”

Dr. Mike: Yeah, and I've heard this before.

So, this was looking at pre-meal—make sure I'm getting this right—water consumption. And the hypothesis was [that] if you have some water in your stomach, you're not going to eat as much; your calorie intake goes down. Is that the gist of it?

Dr. Crystal: Sort of. The researchers in this study—that we’ll go over…that's the idea.

Is Drinking Only Water a Safe Method for Weight Loss? 00:02:00

Dr. Crystal: But there are more mechanisms that are exciting to see as to how water can support weight loss.

Dr. Mike: So, it's not just the feeling [of being] full.

All right, well, let's get into this. This was from [the] 2010 Journal of Obesity. [It] was a randomized controlled trial. Go ahead and tell us about it.

Dr. Crystal: And so, I do want to just say as Dr. Mike mentioned, [it’s] a 2010 study. So, [it’s] older. But [we’re] highlighting this research simply because this is trending.

I'm not sure if you're seeing it, but people are catching on to this idea of water before a meal. And so, I said, “Okay, let's look into it.”

This study was published in the Journal of Obesity. And the researchers wanted to know in overweight and obese middle-aged and older adults, if pre-water exposure reduced meal energy intake. And if that [effect] sustained over a 12-week period—meaning, maybe it helps to decrease intake the first time with their pre-meal, but does it last? Do these effects last?

There were two groups. Both groups were on a hypocaloric diet, meaning a dietary reduction or [fewer] calories taken in. One group consumed 16 fluid ounces of water prior to each daily meal. They did it before three meals.

And then, there was another group: low calorie and no water. And the researchers saw that the weight loss was 4.4 pounds greater in the water group than the non-water group. And the water group showed a 44 percent greater decline in weight over the 12-week period than the water group.

Dr. Mike: So, it was [maintained]; they were able to maintain that.

Do we know what's the timing of drinking this water? I got my meal down, and before I start eating that food, I drink the water.

Dr. Crystal: That's what is indicated. It just said prior to each meal. There were no specific time guidelines provided to the participants.

Dr. Mike: You would think closer to eating, though, would make more sense.

Dr. Crystal: I mean, yeah, it's right before you eat. You sit down, drink your water and start eating.

Dr. Mike: This goes back to something a long time ago; I don't know if you ever knew this. This was like a big fad in the 1990s, Dr. Crystal. It was soup.

Dr. Crystal: Oh yeah.

Dr. Mike: The idea was [to] have an appetizer of soup every time. It was kind of the same idea, instead of just pure water. And it was a low-calorie soup.

It wasn't something heavy, like a “brothy-type” soup. And I think that it was the same idea.

Dr. Crystal: Well, yes and no. So, what…

Dr. Mike: She doesn't like any of my ideas today.

Dr. Crystal: I'm not saying your ideas are wrong, but there's more to it.

How Does Water Affect Metabolism? 00:05:20

Dr. Crystal: That's what I'm saying. The researchers are seeing one: the water is stimulating thermogenesis and resting energy expenditure. When you drink water, it's activating the sympathetic nervous system.

We’re not talking about filling up your stomach [and] you get the sensation of full, so you're eating less. There is a physiological mechanism: norepinephrine is increasing. You are increasing your metabolism by drinking this water.

Dr. Mike: And then you eat the food and now you're going to metabolize it better.

Dr. Crystal: So yeah. You're burning more energy in general versus not drinking the water.

And then going back to your soup. The reason I say yes and no is the water intake is potentially offsetting the consumption of energy beverages. So, if someone would normally have a soda with a meal, you're drinking that water and you're offsetting what you would otherwise be [consuming].

Dr. Mike: So, instead of the coke, you’re drinking the water. There’s calorie reduction right there.

Dr. Crystal: Generally, the researchers are seeing, and [the] data shows, that beverage energy contributes to almost 400 calories per day. If you're not drinking calories and you're having water, then that's another mechanism to the weight loss.

Dr. Mike: I love it, this is fantastic. You already said you're practicing this.

Dr. Crystal: Well, as of yesterday. But here, [this is] so funny. Yesterday I started eating and I was like, “Oh no, my water.” I had to run [and get it].

Dr. Mike: You already forgot.

Dr. Crystal: I already forgot. I'm like, “Where's my water?” Because I can eat an entire meal with no water. My sensation of thirst is not very prominent.

Dr. Mike: I'm like that, too. Once I start eating, I don't usually need something to drink. I just keep going.

There you go. Water consumption right before a meal, 16 ounces, three times a day and you might experience some weight loss. That's fantastic.