If you are hoping to reduce trunk fat, you'll need to create a calorie deficit. Eating a healthy diet, getting the right amount of sleep and exercising will help you to lose fat and improve your health.
The cause of abdominal obesity is a combination of several factors, both known and unknown. According to a March 2015 article published in the American Journal of Clinical Nutrition, the reasons could be anything from endocrine disruptors — certain hormone-mimicking chemicals in our food, drugs and water, to stress. Apart from these concerns, eating more than you burn off and leading a sedentary life contributes to weight gain and increased belly fat.
No matter how you swing it, excess abdominal fat is unhealthy. Harvard Health Publishing says that too much subcutaneous and visceral fat are dangerous to your health. Visceral fat creates a protein called cytokines which trigger low-level inflammation and increases your risks of heart disease and other illnesses. It can also lead to high blood pressure by releasing a protein that constricts your blood vessels.
Subcutaneous fat is less dangerous and in fact can help protect against diabetes by producing a hormone called adiponectin that helps regulate the processing of fats and sugars and is anti-inflammatory. However, having a high amount of belly fat and a waist circumference of 35 inches or larger if you are female, and 40 inches for men, is connected to cardiovascular disease, dementia, asthma, breast cancer and colorectal cancer.
The Prevalence of Abdominal Obesity
The Centers for Disease Control and Prevention's (CDC) data shows that abdominal obesity has been steadily on the rise. In the 17 years spanning 1999 to 2016, the rate of abdominal obesity, as measured by waist circumference, has risen from 46 percent to 59 percent.
In the latest data (2015-2016), these results are broken down by age. The data shows that age correlates to how large your waist is likely to be, with 72 percent of adults aged 70 or over having abdominal obesity. For those ages 60 to 69, the rate is 69 percent; for 40 to 59, it's 63 percent, and 46 percent for 20- to 39-year-olds. The reasons why age is a factor are not discussed.
According to a September 2016 article published in BMC Obesity, the increase in abdominal obesity rates goes above and beyond what is expected from an increase in body weight, particularly in women. In other words, people are gaining weight at higher rates on their abdomen than they are overall. This means that packing on weight mostly on your torso has increased for some other reason than just general weight gain.
Read more: The 3 Secrets to Losing Belly Fat
Exercising to Reduce Trunk Fat
The CDC stresses that physical activity contributes to optimal health, but it is imperative if you are hoping to lose weight or maintain weight. Weight loss occurs when you create a caloric deficit by burning more calories than you consume through your diet. Using physical activity to burn off some of these calories is part of the picture when you're hoping to reduce trunk fat.
The CDC says that a large amount of physical activity is necessary to lose weight if you do not also wish to switch up your diet to create a calorie deficit. The level of exercise needed for this might be difficult for most people. Combining physical activity with a healthy eating plan is your best bet.
The CDC recommends at least 150 minutes of moderate-intensity aerobic activity or 75 minutes of vigorous-intensity aerobic activity or a combination of the two that adds up to about the same amount of exercise each week for health maintenance. It is not entirely clear how much exercise you will need as an individual to lose weight since there are so many factors at play.
Read more: How to Lose Belly Fat Super Fast
Examples of moderate activity include a brisk walk or biking at a casual pace, while vigorous exercise includes things like playing competitive sports or jogging and running. You can use the American Council on Exercise (ACE) calculator for physical activity to determine how many calories you're burning through various exercises.
Current research on the type of exercise that is best for obesity indicates that combining aerobic and resistance exercise is typically your best bet. A December 2016 meta-analysis published in the British Journal of Sports Medicine examined the results of 12 trials that included 555 youth participants. They compared aerobic exercise alone to a combination of aerobic exercise and resistance exercise.
The researchers were looking for how these two types of training affected body mass, fat mass, low-density lipoprotein cholesterol, lean body mass increase, as well as other factors. The meta-analysis determined that combining aerobic and resistance exercise improved body composition, metabolic profiles and states of inflammation in the participants.
When it comes to exercise intensity, a February 2017 meta-analysis published in Obesity Reviews, shows that when comparing high-intensity interval training (HIIT) to medium intensity continuous training, both are successful at reducing whole-body fat mass and waist circumference.
The review says that both are equally able to favorably change body composition, but HIIT requires 40 percent less training time than continuous cardiovascular exercise in the form of running. Interestingly, cycling training was not able to produce fat loss.
The study concluded that short-term moderate-intensity to high-intensity exercise training results in improvements in body composition for people that have overweight and obesity without necessarily reducing their weight. In other words, fat mass and waist circumference are reduced, but weight wasn't necessarily lower, which would indicate an increase in muscle mass at the same time as a loss of fat mass.
So, it is up to you whether you would like to perform moderate-intensity training or if you would like to employ a high-intensity interval training style to save time. Either way, the study indicates that you will see results and reduce trunk fat.
Eating to Reduce Trunk Fat
A March 2019 Advances in Nutrition meta-analysis reviewed several foods and food groups to determine whether or not any particular food group contributed to obesity/overweight, abdominal obesity.
The study discovered that refined grains, red meat and sugar-sweetened beverages are associated with a higher risk of overweight/obesity and abdominal obesity. Particular food groups did not appear to have a significant effect on how much abdominal fat was accumulated.
The Harvard T.H. Chan School of Public Health defines sugary drinks as any beverages that include added sweeteners such as fruit juice concentrates, high fructose corn syrup and sucrose, among others. Examples include sweetened drink powders like iced tea, hot cocoa or orange drinks, sports or energy drinks that contain sugar, sodas, tonic and fruit punch or any fruit juice that isn't 100 percent pure.
Sugary beverages account for the highest number of calories and added sugar consumed by Americans. These drinks contribute to weight gain and abdominal obesity, as well as the risk of Type 2 diabetes, heart disease and other illnesses, as well as an increased risk of premature death, says Harvard Health Publishing.
Avoiding sodas and other sugary beverages and reducing your intake of red meat and refined grains are all ways that you can help decrease your chances of gaining weight on your abdomen and elsewhere.
Conversely, the March 2019 Advances in Nutrition article found that eating whole grains, fruit, nuts, legumes and fish were associated with reduced overweight/obesity and abdominal obesity.
- Keeping within the daily caloric limit for your individual needs, with an approximate 500 calorie per day deficit if you are trying to reduce trunk fat (or lose fat in general).
- Eat plenty of fresh produce, whole grains and low-fat dairy products.
- Maintain a diet that is low in certain fats such as saturated and trans.
- Reducing your levels of sodium and added sugars that come from processed foods.
- Eating plenty of lean proteins such as chicken, fish, eggs, nuts and beans.
The American Council on Exercise provides a daily caloric needs calculator in which you can determine how many calories you need to maintain your weight. If you are hoping to reduce trunk fat or lose weight in general, then you need to create a small deficit. Just how large or small of a calorie deficit is highly personal, but it is recommended to seek the advice of your health care provider.
Lifestyle Factors for Healthy Weight
Other lifestyle factors can contribute to abdominal fat, as well as overweight and obesity in general. An older March 2010 five-year abdominal fat accumulation study in the journal Sleep, found the amount of sleep you get directly contributes to an increase in subcutaneous adipose tissue and visceral adipose tissue.
Those who were younger than 40 years of age and slept for less than five hours were more likely to have a higher level of visceral adipose tissue than those who slept between six and seven hours per day. Sleeping for more than eight hours also contributes to a higher accumulation of visceral adipose tissue and subcutaneous adipose tissue compared to those who sleep between six and seven hours per night.
This association was not found for people older than 40 years. So to increase your chances of losing your tummy fat, you should aim to sleep between six and seven hours each night, especially if you are under the age of 40.
Another factor contributing to abdominal obesity is stress. The University of New Mexico explains that the stress hormone cortisol can have detrimental effects on how your body stores fat. If you are under a lot of stress for a long time, the research shows that you are more likely to have abdominal obesity due to certain enzymes and receptors in the fat cells of your abdomen.
Stress and high levels of cortisol are also associated with increased appetite and cravings for sweets. The University of New Mexico states that research indicates those with higher cortisol levels will naturally reach for foods that are higher in sugar and fat. Cortisol can also interact with other chemicals in your brain, causing an increase in appetite.
If you are hoping to reduce trunk fat, it is essential to practice stress-reduction techniques such as going for walks outdoors and meditating.
- American Journal of Clinical Nutrition: "Are the Recent Secular Increases in the Waist Circumference of Adults Independent of Changes in BMI?"
- Harvard Health Publishing: "Taking Aim at Belly Fat"
- Centers for Disease Control and Prevention: "Indicator Details: Percentage With Abdominal Obesity by Survey Year"
- BMC Obesity: "Changes in Waist Circumference and the Prevalence of Abdominal Obesity During 1994–2008 - Cross-Sectional and Longitudinal Results From Two Surveys: The Tromsø Study"
- Centers for Disease Control and Prevention: "Physical Activity for a Healthy Weight"
- Obesity Reviews: "The Effects of High-Intensity Interval Training Vs. Moderate-Intensity Continuous Training on Body Composition in Overweight and Obese Adults: A Systematic Review and Meta-Analysis"
- Advances in Nutrition: "Food Groups and Risk of Overweight, Obesity, and Weight Gain: A Systematic Review and Dose-Response Meta-Analysis of Prospective Studies"
- Harvard T.H. Chan School of Public Health: "Sugary Drinks"
- Centers for Disease Control and Prevention: "Healthy Eating for a Healthy Weight"
- U.S. Department of Health and Human Services: "2015-2020 Dietary Guidelines for Americans"
- American Council on Exercise: "Daily Caloric Needs Calculator"
- Sleep: "Sleep Duration and Five-Year Abdominal Fat Accumulation in a Minority Cohort: The IRAS Family Study"
- University of New Mexico: "Cortisol Connection: Tips on Managing Stress and Weight"
- British Journal of Sports Medicine: "Concurrent Aerobic Plus Resistance Exercise Versus Aerobic Exercise Alone to Improve Health Outcomes in Paediatric Obesity: A Systematic Review and Meta-Analysis"
- National Heart, Lung, and Blood Institute: "Assessing Your Weight and Health Risk"