You have a date, a party, an important photo — and you want a flat stomach now, not in three months after a strict diet. That is a perfectly legitimate wish, and unlike what some brands claim, there are concrete solutions that work in just a few minutes.
This article brings together the 7 genuinely effective methods to make your stomach visibly flatter over the course of the day — through posture, what you have eaten in the last 24 hours, breathing exercises and, for an instant result, seamless shapewear.
Why your stomach looks bigger than it is
Before you think about how to flatten it, it helps to understand why your stomach looks so rounded to you — because often it is not fat at all. Three common causes:
- Water retention — a meal that was too salty the day before, too little sleep, your hormonal cycle: the body holds on to water and the stomach expands temporarily (1 to 3 cm more around the waist).
- Digestive bloating — certain foods fermenting, eating too fast, not chewing enough: the digestive tract swells and pushes the abdominal wall forward.
- Slouched posture — shoulders rolled forward, pelvis tilted, core switched off: visually, the stomach then looks up to 30% more prominent than it really is.
The good news: all three causes can be reversed in a few minutes to a few hours. Here is how.
7 solutions for an instantly flatter stomach
1. Drink enough water (water, not sugary drinks)
Paradoxically, drinking water reduces water retention. Your body holds on to water when it is short of it; give it a steady supply and it releases it again. Aim for 1.5 to 2 litres spread across the day. Avoid carbonated drinks (CO₂ + sugar = double the bloating).
2. Eat slowly and chew well
Eating too fast means swallowing air and robbing your salivary enzymes of the chance to start digestion. The result: guaranteed bloating two hours after the meal. Put your cutlery down between bites and chew at least 20 times.
3. Avoid bloating foods 24 hours beforehand
If your event is tomorrow: skip white bread, pulses, cabbage, raw onion, fizzy drinks, too much dairy and chewing gum (yes, it makes you swallow air). Reach instead for rice, lean fish, courgette, cucumber and green salad.
4. Have a digestive tea after eating
Fennel, peppermint, ginger, aniseed: these plants speed up gastric emptying and reduce fermentation. One cup 30 minutes after your meal is enough to limit post-meal bloating.
5. Stand with the right posture
Stand tall, shoulders open and back, pelvis tilted slightly forward. Engage your core (gently draw your belly button towards your spine). This posture correction alone can make the stomach look 1 to 2 cm flatter — with nothing else at all.
6. Do breathing exercises
Deep abdominal breathing strengthens the transverse muscle, the one that naturally holds the stomach in like a corset. Lying down or standing, breathe in and let your belly rise, then breathe out and pull it firmly towards your spine (as if you wanted to touch your back with your navel). Do 30 reps morning and evening. Visible after a few days.
7. Wear a tummy control bodysuit
This is the fastest and most effective solution for a specific occasion. A good tummy control bodysuit in seamless fabric makes the stomach visibly flatter — in less than 10 seconds after you put it on — redraws the waist and stays invisible under fitted clothing. It is the difference between a silhouette you own straight away and one you have to work towards for weeks.
The fastest solution: modern seamless shapewear
Every other method takes time (24 h for food, weeks for posture, months for the core). Shapewear is the only solution that works instantly — handy when the event is already an hour away.
Be careful, though: not all shapewear is equal. The old rigid girdles (the control garments of earlier generations) compress hard but leave marks on the skin, slide around and become uncomfortable after two hours. Modern seamless shapewear (with no seams) does the opposite:
- Circular-knit fabric that shapes without squeezing
- No seams pressing into the skin
- Flat or laser-cut edges, invisible under your outfit
- Support for 14 hours and more with no discomfort
At Elya, our seamless pieces are made for exactly this: a stomach that is instantly flatter and comfortable — not the other way round.
Which shapewear to choose to hide the stomach
Three options depending on your outfit:
- Tummy Control Bodysuit — the versatile option. Covers from bust to gusset in one piece. Moderate control for 14 hours and more, ideal for everyday and classic outfits (jeans, dress, skirt).
- Firm Control Bodysuit — a pronounced shaping effect. Firm compression for evenings and occasions where you want the effect to show. Wear for 4 to 8 hours.
- Tummy Control Knickers — the discreet solution when you only want to smooth the lower stomach. Wear under anything, every day.
Solutions compared
| Solution | When it kicks in | How long it lasts | Effort |
|---|---|---|---|
| Seamless shapewear | Instant | As long as you wear it | None |
| Food 24 h before | 12–24 h | 1 day | Low |
| Good posture | Instant (as you straighten up) | As long as you hold it | Constant awareness |
| Breathing exercises | 3–4 weeks | Long term | 10 min/day |
| Drinking enough | 24–48 h | As long as you keep it up | Low |
| Exercise (core training) | 4–8 weeks | Long term | 3–4 sessions/week |
| Diet | Several months | If maintained | High |
Good habits for every day
For a lastingly flat stomach, combine several approaches:
- 1.5–2 l of water a day
- Keep your core engaged through the day (posture)
- 10 minutes of breathing exercises a day
- Cut back on bloating foods before occasions
- Shapewear for the moments when you need the instant effect
Steer clear of strict diets: they lead to the yo-yo effect, slow your metabolism, and the stomach comes back (often bigger) as soon as you stop.
When to see a professional
If your stomach is chronically bloated after every meal, painful, or comes with persistent digestive trouble, see a doctor or a gastroenterologist. It can point to a food intolerance (gluten, lactose, FODMAPs), irritable bowel syndrome or an imbalance in your gut flora — none of which exercise or shapewear can fix.
In short
For an instantly flat stomach, seamless shapewear is the fastest and most effective solution. Combined with good posture, food watched in the 24 hours before an occasion, and breathing exercises over the long term, you get the best of both worlds: a visible effect straight away and a lastingly firmer silhouette.
Discover our Shapewear Bodysuits collection and our Tummy Control Underwear collection — seamless, made in Portugal, built for 14 hours of comfort.
The 5 foods to avoid 24 hours before an occasion
Some foods trigger bloating within a few hours — even in people who normally have no digestive problems. Avoiding them the day before an occasion where you want a flat stomach makes a real, visible difference.
1. Cruciferous vegetables (broccoli, cabbage, cauliflower, Brussels sprouts)
Nutritionally excellent, but rich in fermentable fibre that produces gas in the colon. Save them for the day after your occasion.
2. Pulses (lentils, chickpeas, beans)
Same mechanisms as the cruciferous vegetables, only stronger. Hummus, falafel and chickpea salad are off the menu the day before.
3. Carbonated drinks (sparkling water, sodas, beer)
The CO₂ you take in stays in the stomach and gut for several hours. Go for still water or herbal teas instead.
4. Chewing gum and sugar-free sweets
The sweeteners (sorbitol, mannitol, xylitol) cause bloating and digestive discomfort in 60–80% of people. Avoid them the day before and on the day itself.
5. Dairy in large amounts (yoghurt, cheese, cream)
If you are even slightly lactose-sensitive, a high intake can visibly bloat your stomach. Choose lactose-free versions or avoid them for 24 hours beforehand.
The role of sleep and stress in a flat stomach
Sleep's influence on the way the stomach looks is rarely talked about — yet in the short term it is one of the most decisive factors.
Lack of sleep raises cortisol
Cortisol, the stress hormone, encourages fat storage around the stomach and increases water retention. One night of 6 hours instead of 8 can be enough to make your stomach look visibly bigger the next day.
A full night = a visible effect straight away
Before an important occasion: go to bed early the night before (at least 8 hours). It is the most effective natural strategy after shapewear. Combined with good hydration and avoiding the 5 foods above, the effect is visible from the moment you wake up.
Chronic stress stores belly fat
Over the long term, ongoing stress (work, regularly getting too little sleep) locks fat reserves into the stomach area — an evolutionary survival response. Meditation, yoga and regular gentle movement are the only real answers over time.
5 mistakes NOT to make the night before an occasion
- Skipping dinner in the belief that it will "empty" the stomach. The opposite happens: the stomach produces more acid, you eat more the next morning, and the stomach bloats. Eat light, but eat.
- Drinking a lot of water just before the occasion to "flush yourself out". If anything, the stomach expands. Drink well through the day, quite normally, up until 1–2 h beforehand.
- Trying on new shapewear the day before. You risk discomfort, the wrong size or marks. Test your shapewear at least 5 days before the occasion.
- Taking a laxative. It is genuinely dangerous for digestion and often triggers cramps and discomfort on the day itself. No professional recommends it.
- Doing intense exercise the day before. Muscle soreness, inflammation and the resulting water retention bloat the stomach. Stick to gentle movement (yoga, walking).
The right shapewear for every time of day
Depending on the time and length of your occasion, a different piece is right. Here is how to make the best choice.
Morning and photo shoot (1–3 hours)
Here you can go for a Firm Control Bodysuit with reinforced compression. Short but intense — the shaping effect is at its maximum for photos.
All day (8–10 hours)
Prioritise comfort over compression. The classic Tummy Control Bodysuit or the High Waisted Shapewear Knickers can be worn for a long time without discomfort. The gentle compression holds the stomach all day without getting in the way.
Wedding / occasion over 12–14 hours
The ideal combination: Firm Control Bodysuit (firm control + invisibility) plus Mid-Thigh Shapewear Shorts to stop chafing when you dance. Maximum comfort over a long time.
Short evening (3–5 hours)
Firm Control Knickers with firm compression: a shaping effect that shows straight away, comfortable for an evening standing or sitting that does not run past 5 h.
Tummy Control Knickers€32.99
Tummy Control Bodysuit€47.99
Seamless Shapewear Shorts€37.99
Thong Shapewear Bodysuit€44.99
Read more on the topic
If you want to go deeper into shapewear, with a more practical look at the right pieces, two complementary comparisons:
- Best Shapewear Bodysuit 2026 — our Top 5: our pick of the most effective seamless bodysuits (thong cut, backless, strapless, seamless), with selection criteria and a comparison table.
- Best Tummy Control Underwear 2026 — the full comparison: an in-depth guide to shaping knickers (mid-rise, high-waisted, firm control, seamless), with recommendations by body shape and outfit.
These two articles go deeper into the shapewear solutions mentioned in this guide, with a practical focus on the models best suited to each use.