Flat Stomach basics
Fat in your midriff is the main cause of a prominent stomach. This is noticeable in men and women, and aging plus hormones influence weight gain around the middle.
There are two types of fat in the abdominal area: visceral fat and subcutaneous fat
Visceral and Subcutaneous Fat
Visceral Fat (VAT)
First of all: What is abdominal or visceral fat?
Visceral or Abdominal fat (we use the abbreviation VAT - which is the scientific term: Visceral Adipose Tissue) is the fat that is stored by your body inside your abdomen, it fills the spaces within the abdominal cavity, surrounding the internal organs that are located there, such as the liver, the intestines, the pancreas.
Normally Visceral Fat represents 10% of our body's total fat stores. However in obese or overweight people, fat accumulates in the abdomen in larger quantities.
VAT secretes secretes proteins called cytokines in higher quantities than does the other type of body fat (subcutaneous fat or SAT). These cytokines trigger inflammation and increas the risk for heart disease. It also produces a precursor to angiotensin, a protein that constricts blood vessels causing high blood pressure.
The abdominal fat cells as they grow, ibhibit the production of a hormone (adiponectin) which is a "potent insulin-sensitizing, anti-inflammatory, and anti-atherogenic ... hormone", lower levels of it, lead to obesity and the development of insulin resistance. ( 1 )
This is summed up by Britton in a study conducted in 2013 ( 2 ) which concluded that:
"Visceral adiposity is associated with incident cardiovascular disease and cancer"
Take home point
Visceral Fat or VAT increases the risk of heart disease and cancer.
Subcutaneous Fat (SAT)
Subcutaneous Fat or SAT (for Subcutaneous Adipose Tissue) is the fat that lies beneath your skin as a layer between the muscles and the skin (that is why it is "Sub" = "beneath" and "cutaneous" = "skin"). Its purpose is isolation (think whale blubber), it keeps your body from loosing internal heat or absorbing it from the enviroment.
Your body stores fat as SAT, like the fat on your thighs or hips. And this fat is far less risky than the fat stored in your middle: Abdominal fat is an indicator of higher health risk.
Normally 90% of your body fat is subcutaneous fat (SAT).
SAT also produces cytokines so it is not harmless, on the contrary, in obese people, increased deposits of "abdominal SAT may have a pathogenic function, as additionally evidenced by endocrine and inflammatory responses", in other words SAT inflammes and disrupts hormonal channels just like VAT does ( 3 ).
On its positive side, subcutaneous fat secretes the hormones leptin, an appetite suppresor and also (like VAT does) adiponectin which regulates how fats and sugars are processed, protecting against diabetes. It also has anti-inflammatory effects on our blood vessels.
However the secretion of adiponectin from SAT is reduced in obese subjects (1) which shows that obesity and high body fat, whether SAT or VAT are a bad combination.
Take home point
Subcutaneous Fat (SAT) is also a risk in obese people: it inflammes and increases risk of disease just like VAT does.
Health risks of excessive Visceral Fat
As we mentioned above, the fat that is buried within you, layering your abdomen's vital organs is a real health risk associated with cardiovascular disease, high blood pressure, dementia, asthma, cancer (colorectal and breast cancers), increased blood sugar associated with higher type 2 diabetes risk.
We discuss these risks in our "The Dangers of Belly Fat " webpage:
Fortunately you can do something about Visceral Fat, you can take action and minimize its build-up. You can lose VAT and improve your health. Learn how to do this below.
How fat are you anyway?
First of all, measure your waist; your waist circumference should be less than 31.5 in. (80 cm) in women and less than 37 in. (94 cm) in men.
We discuss the Waist size and the Waist-to-Hip Ratio in our "Waist Size Matters" webpage:
Also calculate your Body Mass Index or BMI , it will give you an idea of where you stand. Ideally your BMI should be 25 or lower.
We discuss Body Mass Index on our "BMI" webpage:
Read More, visit our:
> > BMI Calculator
Now you have a clear picture of where yiou stand, you have your actual BMI and your actual waist size, and you know the goals (waist circumference and a BMI of 25). So now take action!
You gain more visceral Fat as you age
A fact of life is that as people grow older, they increase their body mass, become plumper and, add fat to their mid section. This is a fact of life. Hunter (2010) ( 29 ) studied the possible causes of this "aging" effect:
Gonadal hormones output declines with age, and this contributes to the increase of VAT in both women and men.
In men, testosterone decreases by 1% each year after the age of 30. In women, estrogen drops as they approach menopause which alters fat deposition from thighs and hips to abdomen.
Body weight gain
Adults in industrial countries tend to gain weight as they age, in the US, men increased by 14.1 lbs and women by 19.2 lbs between 1960 and 1991. However, visceral fat grew by 200% in men and 400% in women during the same period.
Loss of Muscle Mass
Sedentary lifestyles lead to a loss of what is known as the body's "fat free mass" or "FFM" (which includes muscle), some stimates show that 60 to 69 year old men lose 14 lbs. of FFM when compared to men aged 20 - 29. For women in the same age groups, the loss is more than 13 lbs.
Lack of exercise combined with a drop in hormones which promote muscle growth are the main culprits.
Additionally as FFM drops (less muscle) but body weight increases, the difference can only be one thing: fat.
Muscle mas loss means less calores burned by the resting body (Basal Metabolic Rate or BMR), a drop in metabolic rate so if calorie intake is maintained with a lower BMR, the extra calories will be stored as fat.
Read More, visit our:
Fat Location Shifts
Finally, as people age, their body fat moves from face, arms and legs to a more central location, inside the abdomen. The reasons for this are not known. Perhaps it is promoted by hormones.
Take home point
Aging increases abdominal fat
But don't sit passively watching your abdomen buldge out, do something! Below we will see what can be done:
How to Get a Flat Stomach
No Quick or Magic Solutions
Special teas, apple cider vinegar, herbal detoxes,TV stomach-flattening gadgets, electrodes, wrapping your midriff in plastic wrap, home gym devices, ab rollers etc. are not effective in reducing your abdominal fat.
You will have to do it the hard way: metabolizing the stored fat (burning it) by exercising and by adjusting your diet. Below we will look into this two-pronged strategy:
Diet for a flat stomach
Diet is a key tool in removing visceral fat. If your energy deficit is around 500 calories a day, in one week you will have eaten 3,500 calories less, and your body will have burned stored fat to generate the "missing" energy it needs. As one pound of fat is roughly 3,500 calories, with this energy deficit you will lose one pound of fat each week.
Although you can't control which fat deposits will be consumed by your energy-avid body, an overall balanced diet will help you lose weight and achieve a healthy weight.
Calcium and Visceral Fat
A study from by Bush, at the University of Alabama, (2010) ( 4 ) involving healthy premenopausal women found that consuming more calcium in the diet was associated with a lower gain of visceral fat. Remember that the recommended dietary allowance of calcium is 1000 mg ⁄ day.
Fiber reduces Visceral and Subcutaneous fat
Hairston (2011) ( 5 ) conducted a five-year study of a group of 1,114 people (roughly 30% African American and 70% Hispanic) and found some interesting relationships between diet and Visceral (VAT) and subcutaneous (SAT) adipose tissue:
- Soluble fiber keeps VAT at bay: "For each 10 g increase in soluble fiber, rate of VAT accumulation decreased by 3.7%", but it did not impact on SAT.
Take home point
Eat more fiber and increase your intake of calcium to reduce VAT
Diet is important in tackling Visceral Fat
Liu et al. ( 6 ) investigated 183 overweight and obese men and women who followed a low calorie diet for a period of 12 weeks. One group ate "pre-portioned prepackaged entrées" the other "self-selected" their diet meals.
They found that diet was the most relevant factor in reducing abdominal fat, regardless of the subjects levels of physical activity:
- Those with more visceral fat or higher weight lost more visceral fat and weight than leaner subjects.
- Greater visceral adiposity loss was not associated with age or physical activity
- The prepackaged entrées group lost more abdominal fat than the "self-selected" diet followers
Take home point
Diet is the key: No significant link between physical activity, strenuous or otherwise, and the degree of visceral fat loss
Exercises for a Flat Stomach
We live sedentary lives, driving to work, to do our shopping, taking escalators or elevators. We do not get enough physical activity in our daily lives.
The guidelines are 150 minutes of moderate physical activity each week (split into 30 minutes over the course of 5 days). But most people don't even manage that.
Any activity is better than none, so one should try to increase physical activity:
- Sit Less and ge active: get your 150 minutes per week of excercise, brisk walking or just parking your car further away from your destination to walk a bit more, taking the stairs instead of the elevator, standing up from your desk and taking a stroll through your office once an hour. Stand up while you talk on the phone.
- Be more active at home: gardening, home chores all of these help you burn calories and improve your physical condition.
Even Walking helps reduce belly fat
Irwin (2003) ( 28 ) studied a group of 173 sedentary overweight postmenopausal women and found that those who exercised with moderate intensity by walking on average 3.5 t days per week for a total of almost 3 hours a week, lost more weight, total body fat, intra-abdominal fat and subcutaneous abdominal fat than those who didn't exercise. Also, those who exercised longer, had greater body fat loss.
Take home point
Walking helps lose weight, SAT, VAT and total body fat.
And, combine diet with exercise:
Exercise reduces Abdominal Fat
Kay and Singh (2006) ( 7 ) reviews studies involving obese or overweight subjects trying to see if physical activity reduced abdominal and visceral fat. They found that 70% of the studies "reported significant reductions" of abdominal fat in comparison to controls.
They concluded that these "studies suggests a beneficial influence of physical activity on reduction in abdominal and visceral fat in overweight and obese subjects".
Take home point
Exercise works for obese or overweight people.
A flat belly will take time and Abs don't work
Working out your excess blubber takes time (no quick-fixes). It will require patience and persistence:
A landmark study by Katch et al., (1984) ( 27 ) at the University of Massachusetts showed that sit-up exercise training does not decrease the diameter of abdominal adipose cells, abdominal SAT or abdominal circumference. So sit-ups won't cut it.
Take home point
Sit-ups don't reduce SAT, waistline or size of abdominal fat cells.
Vispute (2011) ( 8 ) studed a group of 24 men and women, all of them healthy but sedentary. They subjected a group of them to abdominal exercises (a series of 7 abdominal exercises in 2 sets of 10 reps. five days a week for a period of 6 weeks). The other group did no exercise and served as a control.
The study found that "There was no significant effect of abdominal exercises on body weight, body fat percentage, android fat percentage, android fat, abdominal circumference, abdominal skinfold... Six weeks of abdominal exercise training alone was not sufficient to reduce abdominal subcutaneous fat and other measures of body composition".
Those who exercised however had a greater muscular endurance in their abs.
Take home point
Abdominal exercise is not effective enough to reduce abdominal fat in healthy subjects, over a 6 week period.
So maybe abs and crunches don't help when it comes to reducing abdominal fat.
You (2006) ( 9 ) studied 45 obese middle-aged women with an average BMI of 33, and divided them into three groups: one on a low calorie diet, another added low-intensity exercise to the diet, and the third added high-intensity exercise.
After 20 weeks all three groups "reduced body weight, fat mass, percent fat, and waist and hip girths to a similar degree".
However the size of the subcutaneous abdominal adipocytes (fat cells) was smaller in those who exercised. The gluteal adipocytes (fat in the buttocks) dropped similarly in all groups.
Take home point
20 weeks of diet plus exercise in obese women reduces the size of their subcutaneous abdominal fat cells.
Ross and Janssen (1999) ( 10 ) reviewed the evidence on the impact of regular exercise on abdominal fat and found that:
- "Exercise with or without weight loss is associated with reductions in both visceral and subcutaneous fat."
- "There is insufficient evidence to determine whether exercise-induced weight loss is associated with reductions in abdominal fat."
Take home point
You can reduce VAT and SAT even if you do not lose weight. But exercise will not guarantee you lose belly fat.
The type of exercise is important too!
Vigorous Exercise reduces Visceral and Subcutaneous fat
Hairston (2011) (5), whom we mentioned further up, besides finding that soluble fiber helped to reduce VAT gain, also found that:
- Vigorous physical activity reduces VAT: the rate of accumulation of VAT in participants who "sometimes" engaged in vigorous activity decreased by 7.4 % and the rate of SAT fell by 3.6, compared to those reporting rarely or never having done vigorous exercise.
Take home point
Do vigorous exercise to reduce VAT and SAT
Aerobic training is not so effective
If your goal is to reduce the abdominal fat, maybe aerobics is not the best choice: Nicklas et al., (2009) ( 11 ) carried out a test similar to You's (mentioned above)(9). They wanted to find out if aerobic exercise intensity influenced the loss of abdominal fat. They studied 112 overweight and obese postmenopausal women over a period of 20 weeks. They were divided into three groups: low calorie diet, diet plus moderate aerobic exercise or diet plus vigorous-intensity exercise.
- On average all women lost 26.7 lb. (12.1 kg) and loss was similar across the three groups.
- All groups showed similar decreases in abdominal visceral fat (approx. 25%).
Take home point
No preferential loss of abdominal fat when either moderate- or vigorous-intensity aerobic exercise is performed during caloric restriction diet.
Diet alone is as effective as diet plus exercise.
High Intensity Intermittent Training (HIIT) is better
HIIT (High Intensity Interval Training) is also called High-Intensity Intermittent Exercise (HIIE) or Sprint Interval Training (SIT).
It is a form of exercise that involves periods of all-out intensity followed by periods of low intensity exercise or rest.
There are different exercise protocols and the duration of sprint - intense activity periods and the recovery periods are quite variable, from 6 seconds to 4 minutes. Some are quite demanding and may not be suitable for sedentary overweight people, but they can be adjusted to suit individual needs.
It seems that the short, intense bursts of energy burned during HIIT workouts push the body to its limit and increase metabolic rate: your body will burn fat for the rest of the day.
A typical HIIT protocol is the "Wingate":
This type of HIIT involves a spurt of 30 seconds ('all out' intensity), followed by approximately 4 minutes of recovery. This sequence is repeated 4-6 times over a period of up to half an hour. It can be one on an outdoor bike, a stationary bike or running.
Some of the studies mentioned below modified the Wingate to make it easier for sedentary people: they alternated 8-second cycle sprints with 12 seconds of low intensity cycling during a 20 minute period. Which means 60 sprints per session.
Science backs HIIT as an effective way to tackle abdominal fat in a localized manner:
Kuo (2016) ( 12 ) looked into the model that explains how fat is burned during exercise. They found that "anaerobic high-intensity intermittent training produces greater abdominal fat reduction than continuous aerobic training at similar amounts of energy expenditure".
Boutcher (2011) ( 13 ) reviewed studies involving HIIT and found that was effective in reducing both subbcutaneous and abdominal fat, citing the following experimental outcomes:
- 15 weeks of HIIT in untrained young women, led to significantly reduced body mass, abdominal fat (0.15 kg) and significantly more subcutaneous fat (2.5 kg) than those in the steady state aerobic exercise program. Lean women lost less fat than overweight women. (Trapp, 2008) ( 14 )
- 12 weeks of HIIT in overweight young women led to a .12 kg decrease in abdominal fat and a 2.6 kg reduction in subcutaneous fat (8%) (Dunn) ( 15 )
- 8 weeks of HIIT in older type 2 diabetic men: no change in body mass occurred; however, abdominal adiposity was decreased by 44% (Boudou) ( 16 )
- 8 weeks of HIIT one day a week and steady state exercise 2 days a week in Type 2 diabetic men and women: 48% reduction in visceral fat and 18% decrease in subcutaneous fat (Mourier et al.)
- Another study found that trunk muscle mass was significantly increased after 15 weeks of HIIT.
- 24 weeks: subjects in the HIIT group lost more subcutaneous fat compared to a steady state exercise group (Temblay et al.)
- 12 weeks, young overweight men: significantly reduced total, abdominal, trunk, and visceral fat (Heydari) ( 17 )
Giannaki et al. (2012) ( 18 ) recruited 39 healthy adults and divided them into two groups: one doing regular gym training 4 days a week and the other doing High intensity interval training (HIIT) twice a week and regular gym training twice a week. The outcome after 8 weeks was the following:
- Both grups lost total body fat and VAT.
- The HIIT group besides improving cardiorespiratory fitness levels also had a "significantly greater reduction in both abdominal girth and visceral adiposity compared with conventional training".
The team concluded that HIIT was "found to be superior compared with conventional exercise training alone in terms of reducing more visceral adiposity levels."
Take home point
High Intensity Intermittent Training (HIIT) burns more abdominal fat than continuous aerobic training.
Other Belly reducing exercises
Martuscello (2013) ( 19 ) evaluated how effective different types of exercise are, when it comes to flattening your stomach. They found that the squat and deadlift produce activity of the multifidus muscle. They do not recommend doing ball exercises (risk of back injuries and no increase in multifidus muscle activity).
Lumbar Mutlifidus Muscle
The lumbar multifidus acts to extend, laterally flex, and rotate the spine and prevent lower back pain. Disfunction of this muscle leads to atrophic replacement of multifidus muscle with fat. (Freeman, 2010) ( 20 ).
Take home point
Squats and Deadlifts are best for improving core muscles.
Yes, plain and simple squats which consist on sitting down with your legs set apart the distance of your hips, keeping your back straight and not letting your knees protrude forward beyond the tips of your toes. Stop when you reach a sitting position slightly above knee height. And then rising back up again to an upright position.
You can do this holding a weight to your chest or with dumbells in each hand. You can do it slowly or at a quick tempo. There are many options.
This exercise consists on lifting a weight off the floor (if that is too difficult, you can elevate the bar resting it on a sturdy box). To do it safely you should keep your feet hip-width apart, use an overhang grip, and keep a flat neutral spine throughout the whole move.
Keep your shoulders back and down.
Do the "hip hinge": imagine your hips are a hinge, so when you move up, you sit back (not down like in the squat), your bottom moves back and you stand up.
Do it safely, start with light weight. The safest option is to have a gym pro coach you to do the move safely and then do it by yourself.
Warm up before starting an do 3 to 6 sets of 4 or 5 reps each.
Combine Diet with Exercise
But remember, firming your muscles sandwiched between visceral fat and subcutaneous fat won't create a flat tummy, you also have to burn off the fat and that is achieved with a lower caloric intake: dieting.
There are also other factors that can help you tackle a plump midriff:
Some Tricks to flatten your Stomach
There are several factors apart from diet and exercise that can accumulate fat in your abdomen. You can act on them too:
Molenaar (2009) ( 21 ) found that men who smoked had a higher SAT than those who never smoked, and that former smokers had the highest SAT (yes, quitting contributes in some cases to an increase in body weight). Men and women who smoke or had smoked had a higher VAT than those who never smoked.
Cut down on Alcohol
Molenaar also found that men who dran more than 14 drinks a week had higher VAT than those who drank less. (SAT was not affected by drinking). In women, VAT was similar in those drinking more than 7 drinks ⁄ week to those who drank less, and amazingly, drinking women hada a lower SAT than teetotallers (perhaps due to hunger inhibition from alcohol's "empty" calories).
Sleep the correct amount of time: neither too much nor too little. Chaput (2014) ( 22 )studied 293 subjects for a 6-year period. All participants gained VAT during the study (reflecting the current "fattening" trend in America, and also the ageing of the study group). But fat gain was not the same for all participants:
- Those who slept too little (less than 6 hours per day) and those who slept too much (more than 9 hours per day) "gained significantly more VAT than those reporting sleeping 7-8 hours a night".
- A small change such as increasing sleep duration from less than 6 to around 7 - 8 hours per day resulted in a lower VAT Gain.
Mood and Visceral Fat
Mood has an influence on abdominal fat but not on subcutaneous fat according to Everson-Rose (2009) ( 23 ). The study involved 409 middle-aged women and found that:
- Increasing the depression rating by 1 point (using the Center for Epidemiological Studies Depression Scale or CES-D) increased VAT in 1.03 cm2.
- Women with a CES-D score of 16 or higher, had 24.5% more VAT than women with lower scores.
- SAT was unrelated to depressive symptoms.
Food allergies, auto immunity and food intolerances
A study by Foley (2014) ( 24 ) reports that "Bloating and [abdominal] distension, which are possibly separate but interrelated conditions, together comprise one of the most commonly described gastrointestinal symptoms. Bloating and distension have been reported in up to 96% of patients with irritable bowel syndrome (IBS) and in 20% to 30% of the general population, with the majority of those affected describing their symptoms as either moderate or severe."
There are many possible causes for abdominal distension such as:
Celiac disease (CD) affects about 1% of the population. It appears in genetically susceptible people as a reaction to dietary gluten (a protein found in wheat, rye and barley).
This immune-mediated disease is chronic and one of its outstanding symptoms, reportd in almost 85% of cases is bloating and abdominal distension. A symptom which can continue for up to 5 years after adopting a Gluten Free diet, and is more noticabla among women.
The only effective treatment is to follow a gluten-free diet. ( 25 )
Non-celiac gluten sensitivity
Catassi (2015) ( 26 ) mentions the Non-celiac gluten sensitivity (NCGS) as a syndrome with similar symptoms to CD, and is triggered by the ingestion of gluten-containing food in subjects who are not affected by either celiac disease or wheat allergy. It affects adults and especially women in the age group of 30-50 years. Bloating is one of its main symptoms.
Gases and Fermentation: gut bacteria and their food
Bacteria in your intestines break down and ferment certain types of foods generating methane gas. This can cause distension and discomfort.
FODMAP is the acronym for a group of sugars which are poorly absorbed by the small intestine and ferment quickly in the gut. They are short-chain carbohydrates and the name stands for "Fermentable Oligo- Di- and Monosaccharides and Polyols".
Some examples of these sugars are: lactose found in milk, fructose, mannitol and sorbitol found in fruits.
Foods that contain large amounts of FODMAPs and should be avoided by people with IBS (Irritable Bowel Syndrome) (see a List of high FODMAP foods) include: milk, fruits, bread, cereals, cream, fruit juices and beans, among others.
Lactose intolerance which is prevalent among most ethnic groups (with some exceptions such as northern Europeans) is the inability to digest lactose, a sugar that makes milk sweet. This also causes bloating.
Probiotics may be helpful against bloating (24) but only those containing bifidobacteria, which do not generate gas during fermentation.
Flat Stomach: a Recap
If you are concerned about a fat midsection, take action now, it is a serious health risk.
Start by measuring your waistline and calculating your BMI, that will tell you where you stand now.
Flattening your belly by reducing the amount of subcutaneous and visceral fat is not an impossible task, it requires determination and hard work:
- Diet: reduce your caloric intake to burn stored fats. Eat a healthy and balanced diet.
- Exercise: vigorous exercise and especially HIIT focus on reducing visceral fat.
- Lifestyle: cut back on smoking and alcohol; sleep 7 or 8 hours and keep active.
- Other factors: check if you are allergic or have IBS, Celiac disease or are lactose intolerant and adjust your diet accordingly.
Cite this article:
A. Whittall. ©2018. Tips for a flatter belly. Patagonia Wellness, 11 Oct. 2018. http://www.patagoniawellness.com/fitness/tips-for-a-flatter-belly.html
Subject: How to flatten your stomach. Tips for getting rid of visceral fat (abdominal fat) and subcutaneous fat. Diet, exercise and health risks and benefits.
References and Further Reading
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(2) Britton KA, Massaro JM, Murabito JM, Kreger BE, Hoffmann U, Fox CS. Body Fat Distribution, Incident Cardiovascular Disease, Cancer, and All-cause Mortality (Body fat and disease). Journal of the American College of Cardiology. v. 62, no. 10 (): 921-925. DOI: 10.1016/j.jacc.2013.06.027
(3) I. Schlecht, B. Fischer, G. Behrens, Mi. Leitzmann, (2016). Relations of Visceral and Abdominal Subcutaneous Adipose Tissue, Body Mass Index, and Waist Circumference to Serum Concentrations of Parameters of Chronic Inflammation, Obes Facts. 2016 Jun; 9(3): 144-157. 2016 Jun 1. doi: 10.1159/000443691
(4) Nikki C. Bush et al., (2010). Dietary calcium intake is associated with less gain in intra-abdominal adipose tissue over 1 yr, Obesity (Silver Spring). 2010 Nov; 18(11): 2101-2104. 2010 Mar 4. doi: 10.1038/oby.2010.39
(5) Kristen G. Hairston (2011).Lifestyle Factors and 5-Year Abdominal Fat Accumulation in a Minority Cohort: The IRAS Family Study, Obesity (Silver Spring). 2012 Feb; 20(2): 2011 Jun 16. doi: 10.1038/oby.2011.171
(6) FX Liu et al., (2017). Factors Associated with Visceral Fat Loss in Response to a Multifaceted Weight Loss Intervention, J Obes Weight Loss Ther. 2017; 7(4): 346. 2017 Aug 14. doi: 10.4172/2165-7904.1000346
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