HYDROGEN WATER DRINKWARES
WATER BOTTLE GUIDES
Leave a comment / Blog / By Zainab.K / 4 oct 2026
A BPA-free water bottle is not necessarily plastic-free. A glass or stainless-steel body may still have plastic in the lid, spout, gasket, or straw.
For lower plastic contact, compare options such as Purifyou, Mayu, or Klean Kanteen Reflect. If keeping drinks hot or cold matters more, an insulated stainless-steel bottle such as Hydro Flask may be a better fit. For lightweight outdoor use, titanium is another option to consider.
Before buying, check the full water path not just the bottle body and choose the material that best matches how you plan to use it.
Your bottle says BPA free. Your water may still run through a plastic spout, past a plastic gasket, or down a plastic straw every time you drink. The label addresses BPA, but it does not necessarily mean that every surface your water touches is plastic free.
Many bottles marketed as BPA free can still contain plastic at water contact points. While researching bottle materials, manufacturer specifications, product listings, and customer feedback, I found that the body material alone does not tell the whole story.
A bottle may have a glass or stainless steel body while still using plastic in the lid, spout, gasket, or straw. These contact points matter because they are part of the path water follows during storage and drinking.
Based on the product information reviewed for this guide, Purifyou stands out for its glass body and stainless steel lined lid designed to minimize plastic contact with the water. Rather than relying only on a “plastic free” or “BPA free” label, it is important to check the construction of the lid and other contact points.
Material choice matters beyond plastic contact. Published research and material information can also help buyers understand differences between glass, stainless steel, and plastics such as Tritan.
Lead is another factor to research when comparing insulated stainless-steel bottles. Manufacturer disclosures and available product information vary between brands, so lead-free construction should be checked using current brand specifications.
For this guide, I reviewed manufacturer information, product specifications, available customer feedback, and published research to compare bottle materials and water contact surfaces.
If you’re choosing a BPA free bottle, the material of the bottle itself is only part of the picture. You also need to look at the parts your water actually touches.
A glass or stainless steel bottle, for example, may still have a plastic lid, spout, or straw. That’s easy to miss when you’re shopping because the main material usually gets most of the attention.
While researching this guide, I compared bottle specifications, manufacturer information, product listings, and available customer feedback. One thing became clear: you need to check the whole water path, not just the bottle body.
When you see a bottle described as glass or stainless steel, take a closer look at the smaller parts.
Check the:
These details matter because your water can come into contact with them during storage or drinking.
Purifyou is a useful example from my research. According to the product information I reviewed, it combines a glass body with a stainless-steel-lined lid. That’s the kind of detail worth looking for if reducing plastic contact is important to you.
This is where “BPA-free” can get confusing.
BPA free tells you something about BPA, but it does not automatically mean the product is plastic free. Other materials and BPA alternatives may still be used.
Research has also looked at microplastic shedding and chemicals with estrogenic activity in plastic products. A 2011 study published in Environmental Health Perspectives, for example, reported estrogenic activity in many commercially available plastic products, including some marketed as BPA-free.
So instead of stopping at the BPA free label, check what the bottle, lid, spout, and straw are actually made from.
If you’re considering an insulated stainless steel bottle, there’s another detail worth checking: how the vacuum seal is made.
Some insulated bottle manufacturing processes have used lead containing materials around the vacuum sealing point at the base of the bottle. This area is generally separate from the water chamber, but it’s still something you may want to check when comparing brands.
Before buying, look for:
Hydro Flask states that it introduced a lead free sealing process in 2014. Other manufacturers may use different processes, so don’t assume that “stainless steel” automatically means “lead free.”
Answer 3 quick questions and find a bottle material that fits your routine.
Choose what best matches your routine.
Pick the feature you don't want to compromise on.
Think about the lid, gasket, spout and straw too.
MATERIAL TO CONSIDER
Not all bottle materials work the same way. Some are better for reducing plastic contact, while others make more sense for insulation, weight, or everyday convenience.
For this guide, I compared manufacturer specifications, product details, and available customer feedback. One thing stood out: the bottle body is only part of the decision. The lid, spout, gasket, and straw matter too.
Here’s what to know about each material before choosing one.
If material safety is your main priority, you can also compare my safest non toxic water bottles for more bottle options.
Glass is one of the more inert materials used for water bottles. It does not easily retain flavors and is a practical choice for water and acidic drinks.
But a glass body does not automatically mean a plastic free water path. If the bottle has a plastic lid, spout, or straw, your water can still come into contact with plastic.
Pros
Cons
Purifyou: It uses a glass body with a stainless-steel-lined lid designed to minimize plastic contact. The listed regular price was $32.97.
Mayu: Its borosilicate bottle is listed as BPA free, BPS free, and lead-free at $39.00. The impeller and lid require hand washing, so check the current lid specifications if minimizing plastic contact is important to you.
Sunkey: The 32 oz glass bottle was listed at $17.99 and comes with a bamboo lid. Just remember that a bamboo exterior does not necessarily tell you what material is used inside the lid.
Worth noting: Purifyou stands out here because of its stainless-steel lined lid. Still, checking the latest manufacturer specifications before buying is a good habit.
Food grade 304 stainless steel, also known as 18/8 stainless steel, is commonly used in reusable water bottles. It is durable and works well for everyday use.
The bigger choice is between single wall and insulated stainless steel.
A single wall steel bottle paired with a steel lid can minimize plastic in the water path. The trade off is insulation, so your drink will not stay cold or hot as long as it would in a vacuum insulated bottle.
Insulated stainless steel is more useful when temperature retention matters. Hydro Flask, for example, lists its 24 oz double-wall bottle as keeping drinks cold for up to 24 hours and hot for up to 12 hours.
But don’t forget the lid. A stainless steel body does not automatically mean every surface your water touches is stainless steel.
If stainless steel fits your needs better than glass, see my best stainless steel water bottles for a closer comparison of everyday options.
If you carry your bottle all day, titanium has one obvious advantage: weight.
Titanium is lightweight and odor resistant. When paired with a metal lid and suitable contact surfaces, it can also keep plastic out of the main water path.
Taima’s pure titanium bottle is listed at around 159 grams with an MSRP of $159.95.
The trade offs are straightforward:
So if you are paying extra for titanium to avoid plastic contact, make sure the lid does not undo that benefit.
Ceramic is another inert option, but it comes with practical compromises.
It is generally heavy and fragile, which makes it less convenient for commuting, hiking, or everyday carry. Ceramic bottles with suitable non plastic lid designs can also be harder to find.
For that reason, ceramic makes more sense for a desk or home setup. If you choose one, check the lid construction rather than assuming the ceramic body makes the whole bottle plastic free.
Copper has antimicrobial properties, but that does not automatically make a copper bottle the right choice for everyone.
Copper can affect taste, and some bottles use an internal lining to separate the drink from the metal. That adds another material to consider when checking the water path.
Before buying, look at:
If minimizing plastic contact is your priority, these details matter more than simply seeing “copper” on the product label.
Aluminum is lightweight, but the inside of the bottle deserves a closer look.
Many aluminum bottles use an internal polymer liner to separate the drink from the aluminum. That means an aluminum body should not automatically be treated as plastic-free.
Liberty Bottleworks is one example included in this guide. If you are considering an aluminum bottle, check both the internal liner and lid materials before buying.
For someone trying to minimize plastic contact, aluminum generally requires more careful checking than glass or stainless steel.
| Material | Main Advantage | Main Trade-Off | What to Check |
|---|---|---|---|
| Glass + steel-lined lid | Minimizes plastic contact | Heavy and breakable | Lid and gasket |
| Single-wall stainless steel | Durable and simple | No insulation | Lid material |
| Titanium | Lightweight | Expensive | Lid and contact surfaces |
| Ceramic | Inert material | Heavy and fragile | Lid design |
| Insulated stainless steel | Temperature retention | Lid may contain plastic | Lid, spout, and vacuum seal |
| Aluminum | Lightweight | Often uses an internal liner | Liner and lid materials |
Don’t judge a bottle by the body material alone. Check the full water path before you buy.
Check the main material.
See what touches the water.
Check what you drink through.
Check the sealing material.
Check whether plastic touches water.
You’ve picked the bottle material. Now look at the parts your water actually touches.
A glass or stainless steel body is only part of the picture. The spout, gasket, straw, and inside of the lid can all become water contact points during storage or drinking.
While comparing bottle specifications and product details, I noticed how easy it is to focus on the body material and overlook these smaller parts. That’s why I now look at the full water path, not just the material named on the front of the bottle.
Before choosing a bottle, check these four areas:
Expert Tip: Trace the water path from the bottle to your mouth. A glass or stainless steel body tells you very little about the lid, spout, gasket, or straw.
MiiR, for example, lists BPA free polypropylene (#5) and Eastman Tritan in some of its lid designs. These may be BPA free materials, but they are still plastic contact points.
This is one detail I would pay close attention to when comparing bottles.
Some bottles use wood or bamboo on the outside of the lid with stainless steel on the inside. The exterior may be the first thing you notice, but the inside matters more when you’re checking what your water actually touches.
Purifyou uses a stainless steel lined lid with its glass bottle. Klean Kanteen Reflect uses a bamboo cap with a stainless-steel interior.
But don’t stop at the lid lining. Also check:
A “stainless steel under lid” claim describes one part of the bottle. It does not automatically mean every water-contact surface is stainless steel.
Gaskets are easy to overlook, but they play an important role in preventing leaks.
Food grade silicone is commonly used for these seals. If you’re trying to understand everything your water touches, include the gasket in your check rather than focusing only on the bottle and lid.
It also needs regular cleaning. Residue and moisture can collect around the seal, so removing and cleaning it helps keep this part of the bottle clean.
Klean Kanteen Reflect, for example, uses food grade silicone for its gasket alongside its stainless steel interior.
Straws and spouts are another detail worth checking before you buy.
A bottle can have a glass or stainless-steel body and still include:
If minimizing plastic contact is important to you, a no straw design or metal drinking surface can simplify the water path.
Purifyou uses a no straw design, removing one potential plastic contact point.
The same idea applies to the spout. If a stainless steel bottle uses a plastic drinking spout, your water can still come into contact with plastic when you drink.
Before buying, follow this simple path:
Check the material at each point. This gives you a clearer picture than relying on a “glass,” “stainless steel,” or “BPA-free” label alone.
Lead concerns around stainless steel bottles can sound alarming, but the issue is more specific than simply asking whether a bottle “contains lead.”
With vacuum insulated bottles, the detail worth checking is how the vacuum between the inner and outer steel walls is sealed. This part of the construction is separate from the lid, spout, gasket, and other surfaces your drink may touch.
If you’ve already checked those water contact points, the vacuum seal is the next detail to understand.
A vacuum insulated bottle is made with two stainless steel walls and a vacuum between them. During manufacturing, the opening used to create that vacuum needs to be sealed.
Some bottle manufacturing methods have used lead containing material at this sealing point. That is where much of the concern around lead in insulated bottles comes from.
There is an important distinction, though: the vacuum sealing point is normally outside the inner chamber that holds your drink.
So there are really two separate questions:
For buyers who prefer to avoid lead anywhere in the product, the first question still matters even when the sealing point is outside the water contact area.
Think of an insulated bottle as one stainless-steel container sitting inside another.
The space between those two walls is evacuated to create a vacuum. This helps reduce heat transfer and allows the bottle to keep drinks hot or cold for longer.
After the vacuum is created, the small manufacturing opening has to be permanently sealed.
Different manufacturers can use different materials or processes for this step. That means two bottles made from similar stainless steel can still differ in how their vacuum construction is sealed.
While looking into how different bottle brands describe their vacuum construction, I noticed that “lead free” is much more useful when the company explains what it actually uses instead.
A simple statement on a product page gives you less information than a manufacturer that clearly identifies its sealing material or construction method.
That’s why I look beyond the front label and check the manufacturer’s own specifications when comparing lead-free options.
For example, Klean Kanteen currently says its products are lead-free and explains that its vacuum insulated vessels use silica or glass plugs rather than lead based alternatives.
The important part here isn’t just the words “lead free.” It’s the extra detail explaining how the bottle is constructed.
You don’t need to inspect the bottle yourself to check this.
Start with the manufacturer’s current product specifications, FAQ, or materials information. If the answer still isn’t clear, these are useful questions to ask:
Look for specific answers rather than general reassurance.
A company that explains the sealing material or manufacturing process gives you more useful information than a product page that simply says “lead safe” or “lead-free” without further context.
This distinction is easy to miss.
A bottle can potentially use a lead containing material somewhere in its construction without that material being part of the surface your water touches.
At the same time, some buyers may prefer a bottle made without lead anywhere in its construction.
Neither question should be replaced by the other.
If your main concern is water contact, check whether the material is exposed to the drink.
If your goal is avoiding lead anywhere in the bottle, look for a manufacturer that clearly describes the vacuum sealing method and its lead free construction.
Before choosing an insulated stainless-steel bottle, follow these four checks:
A “lead-free” claim should be checked alongside the bottle’s overall construction. The body and vacuum seal matter, but so do the surfaces your water actually touches, including the lid, gasket, spout, and straw.
While comparing manufacturer information and available product details, I noticed that brands do not always provide the same level of detail about these components. Check the latest specifications before buying, especially when construction or lid designs can vary by product.
| Brand / Bottle | Lead-Free Information | Water-Contact Surface | What to Check |
|---|---|---|---|
| Hydro Flask View on Amazon | Manufacturer describes its current sealing process as lead-free | Lid design can include plastic components | Check the exact lid and current construction details |
| Klean Kanteen Reflect View on Amazon | Listed as lead-free | Bamboo cap with stainless-steel interior | Check the gasket and current product specifications |
| Mayu Glass Bottle View on Amazon | Listed as lead-free and BPA/BPS-free | Borosilicate glass with stainless steel under the lid | Check the lid and gasket materials |
| Ohelo Steel Tumbler View Product | Listed as lead-free | Lid materials should be checked by model | Verify the current lid specifications |
| MiiR View on Amazon | Construction details can vary by product | Depends on the specific lid and model | Confirm the current manufacturer's specifications |
The checklist names the brands. This table lets you compare them factor by factor.
The main question is simple: does water come into contact with plastic at the lid, spout, gasket, or straw? The bottle body is only one part of the picture.
While comparing manufacturer specifications and available product details, I noticed that bottles described as glass, stainless steel, or plastic free can still differ significantly in their lid and drinking components. Purifyou, for example, stands out for its stainless steel lined lid interior, while other bottles may not clearly specify every water contact material.
| Bottle / Brand | Body Material | Lid / Spout Material | Lead Info | Dishwasher-Safe? | Insulation |
|---|---|---|---|---|---|
| Purifyou Glass Water Bottle View on Amazon | Borosilicate glass | Polypropylene cap with stainless-steel lid interior | Lead-Free | Yes Hand-washing is safest | Non-insulated |
| Klean Kanteen Reflect View on Amazon | 18/8 stainless steel | Bamboo Cap with all-stainless interior | Lead-Free | Bottle: Yes Bamboo Cap: hand-wash | Depends on Reflect model |
| MAYU Glass Bottle View on Amazon | Grade A borosilicate glass | Glass bottle system | Lead-Free | Glass: Yes Hand-wash other components | Non-insulated |
| Sunkey Glass Bottle View on Amazon | Glass | Bamboo-style lid | No manufacturer lead-free claim found | Check product care instructions | Non-insulated |
| Taima Titanium Bottle View Product | Pure titanium | Titanium construction | No manufacturer lead-free claim found | Yes | Non-insulated |
| Ohelo Steel Tumbler View Product | 18/8 stainless steel | Leakproof sip lid | Lead-Free Lead-free solder | Yes | Up to 12h cold / 6h hot |
| Hydro Flask 24 oz View on Amazon | Stainless steel | Flex Cap | Lead-Free Sealing No lead used in vacuum sealing | Yes Powder-coated bottles | Vacuum insulated |
| Lifefactory Glass Bottle View on Amazon | Glass with silicone sleeve | BPA-free polypropylene cap | No manufacturer lead-free claim found | Yes Cap: top rack | Non-insulated |
| Soma Glass Bottle View on Amazon | Glass | Lid varies by bottle version | No manufacturer lead-free claim found | Check product care instructions | Non-insulated |
| bkr Glass Bottle View on Amazon | Soda-lime glass with silicone sleeve | Polypropylene cap + silicone gasket | Lead Safe Lead not detected in glass | Yes Cap: top rack | Non-insulated |
| MiiR View on Amazon | Stainless steel | Varies by model | No universal lead-free claim Check exact MiiR model | Hand-wash recommended Some lids: top-rack dishwasher-safe | Vacuum-insulated models available |
| YETI Rambler View on Amazon | 18/8 stainless steel | Cap varies by Rambler model | Lead Used in Seal Sealing bead is encapsulated beneath the base barrier | Yes | Double-wall vacuum insulation |
| Stanley View on Amazon | Stainless steel | Lid varies by model | Lead Used in Vacuum Seal Sealing material is enclosed beneath the base barrier | Varies by model Check dishwasher marking on product | Vacuum-insulated models available |
| Liberty Bottleworks Aluminum View Product | Recycled aluminum | Food-grade liner + cap | No explicit lead-free claim found | Check exact model | Non-insulated |
The right bottle material depends on how and where you plan to use it. A glass bottle can make sense at a desk, while stainless steel may be more practical for travel and titanium can be useful when keeping weight low matters.
While comparing bottle materials, manufacturer specifications, and available product information, one thing became clear: there is no single best material for every situation. The better approach is to match the bottle to your use case, then check the lid, gasket, spout, and straw for additional water contact materials.
For desk or office use, glass is one of the more practical choices because insulation and low weight may matter less when the bottle stays in one place.
The Purifyou Glass Water Bottle uses a glass body and a stainless steel lined lid designed to minimize plastic contact. The Mayu Glass Bottle uses borosilicate glass and is listed as BPA free, BPS free, and lead free.
When comparing glass bottles, check:
Glass is heavier and more breakable than stainless steel or titanium, but those trade-offs may be easier to accept for desk use.
If keeping water cold or drinks hot is the priority, vacuum insulated stainless steel is generally the more practical option.
Growing up in a very hot climate made good insulation one of the things I pay the most attention to when choosing a water bottle.
The Hydro Flask 24 oz is a double wall stainless steel option designed for temperature retention. The Ohelo Steel Tumbler is another insulated steel option mentioned in this guide.
However, don’t stop at the stainless steel body. Check the lid and drinking surface as well. Some insulated bottles use plastic components in the lid, cap, or spout, which means the water path may not be completely plastic free.
If minimizing plastic contact matters more than insulation, the Klean Kanteen Reflect 27 oz is worth comparing. Its bamboo cap has a stainless steel interior, although its single wall construction does not provide the same temperature retention as a vacuum insulated bottle.
For lemon water, kombucha, and other acidic drinks, borosilicate glass is a simple material to consider because it is relatively inert and does not easily retain flavors.
A glass bottle paired with a stainless steel lined lid can also help reduce plastic along the main water path.
When choosing one, still check the gasket and the underside of the lid. A glass body alone does not tell you what the drink touches when you tip the bottle.
For hiking, outdoor use, or situations where weight matters, titanium is worth considering.
The Taima Pure Titanium Bottle is listed at roughly 159 grams. Titanium is lightweight and resistant to odors, making it an interesting alternative to heavier glass and stainless-steel bottles.
The trade off is price. Titanium bottles can cost considerably more than glass or stainless steel alternatives.
Also check the cap before buying. A titanium body does not automatically mean the entire water path is plastic free. If minimizing plastic contact is your goal, look at the cap, gasket, spout, and any other surfaces the water touches.
For a less expensive alternative, a single wall stainless steel bottle such as the Klean Kanteen Reflect may make more sense, although it is heavier than titanium.
Price can narrow the choices quickly. Based on the product prices gathered for this guide, the options fall into roughly these ranges:
Prices and availability can change, so check the current product listing before buying rather than treating these figures as guaranteed prices.
| Your Priority | Material | Bottle Example | Trade-Off |
|---|---|---|---|
| Desk & Office | Borosilicate Glass | Purifyou / Mayu | Heavier & breakable |
| Hot / Cold Retention | Insulated Stainless Steel | Hydro Flask / Ohelo | Check lid materials |
| Lower Plastic Contact | Glass / Single-Wall Steel | Purifyou / Klean Kanteen Reflect | Less or no insulation |
| Acidic Drinks | Glass | Purifyou / Mayu | Breakability |
| Outdoor Carry | Titanium | Taima | Higher price |
| Budget | Glass / Single-Wall Steel | Sunkey / bkr / Klean Kanteen | Features vary |
Choosing the right bottle is only part of the job. Lids, gaskets, straws, and other small parts also need regular cleaning, especially because moisture can remain trapped around seals and narrow crevices.
While looking into bottle care guidance, I noticed that cleaning instructions often differ between the bottle body and the lid components. That makes it important to check each removable part separately rather than treating the whole bottle the same way.
It is easy to focus on the bottle body and overlook the silicone gasket hidden inside the lid. Because moisture and residue can collect around seals and grooves, these areas deserve extra attention.
A simple cleaning routine is:
Always check the manufacturer’s care instructions before removing small components or putting them in a dishwasher.
For material specific cleaning steps, see my complete guide on how to clean a water bottle, including lids, seals, straws, glass, and stainless steel.
Silicone gaskets can wear down over time. Regular washing, repeated use, and compression inside the lid may eventually affect their shape or sealing ability.
Consider replacing a gasket if you notice:
A damaged seal can make the bottle harder to keep clean and may also affect its ability to close securely.
Different bottle materials require different care, so check the body and lid separately before washing them.
For example, Klean Kanteen provides separate care guidance for the Reflect’s stainless steel body and bamboo cap, while Mayu also gives different cleaning instructions for its glass carafe and lid components.
Stainless steel needs regular care too, especially around the lid and seals. Here’s my full guide to cleaning a stainless steel water bottle properly.
A few simple habits can also help:
The main rule is simple: don’t clean only the bottle body. Pay attention to every removable part that regularly comes into contact with your drink.
IS STAINLESS STEEL SAFE?
Yes. Food-grade 304 (18/8) stainless steel is durable, dishwasher-safe, and sheds essentially zero microplastics. The
steel itself is inert and does not leach into water. One caveat: lead, which I address below.
DOES GLASS KEEP WATER COLD?
No. Single-wall glass does not insulate at all. Double-wall borosilicate, like the bkr 500mL at $14, offers limited
insulation, and less than a vacuum steel bottle. Glass is for purity and taste, not temperature retention.
IS TRITAN REALLY PLASTIC-FREE?
No, Tritan is a plastic, and the BPA-free label creates false confidence. Tritan can leach BPS and show estrogenic
activity at warm temperatures. Yang et al. (2011) found that most plastic products release estrogenic chemicals,
including some BPA-free replacements. If you want zero water contact with plastic, Tritan is not the answer
ARE ALUMINUM BOTTLES SAFE?
Aluminum bottles almost always have an internal polymer liner that may leach. They are not truly plastic-free. For
zero plastic contact, I do not recommend them.
DO I NEED TO WORRY ABOUT LEAD IN MY STAINLESS STEEL BOTTLE?
Yes. Recent coverage has highlighted lead soldering in some insulated bottles, and lead soldering was used in
most stainless bottles until recently. Hydro Flask pioneered lead-free construction in 2014, but not every brand
followed. Choose verified lead-free brands like Hydro Flask, Klean Kanteen, Mayu, and Ohelo, and confirm with the
manufacture
WHAT IS THE SAFEST MATERIAL FOR ACIDIC DRINKS LIKE LEMON WATER OR KOMBUCHA?
Glass is the most inert choice. It will not retain flavors or react with acids. Stainless steel handles most acidic drinks
fine, but glass removes any doubt.
HOW DO I KNOW IF NO PLASTIC TOUCHES MY WATER?
Check the lid, spout, gasket, and straw. Look for stainless-steel-lined or stainless-under-lid designs, and avoid plastic
spouts and straws. The bottle body is only half the audit.
A BPA free label is a good starting point, but it does not tell the whole story. The bottle body may be glass or stainless steel, while the lid, gasket, spout, or straw can still use different materials.
The best bottle depends on how you plan to use it. Glass works well for desk use, insulated stainless steel helps with temperature retention, and titanium is useful when keeping weight low matters.
Before buying, check the full water path, not just the bottle body. Look at the lid, gasket, spout, and straw, and follow the manufacturer’s care instructions.
In the end, every surface your water touches matters.
Hey there, I’m Zainab.
I created Water Bottles Experts to remove the guesswork from choosing the right water bottle for your lifestyle.
Every product featured here is evaluated with real-life use in mind, focusing on durability, insulation, and everyday convenience.
After learning, how consistent hydration impacts overall well-being, I now share practical guides, comparisons, and honest reviews to help you make informed, confident choices about water bottles that truly work for daily life.
Over the years, I’ve researched and compared dozens of water bottles, focusing on material safety, insulation performance, and long-term usability rather than short-term trends.