Sustainable Weight Loss: What the Science Says About Which Weight-Loss Tips Really Work
- Dr Melissa Godfrey
- 5 days ago
- 5 min read
Losing belly fat and achieving sustainable weight loss isn’t just about looking good, it’s about protecting your long-term health. With obesity in South Africa reaching alarming levels, more people are searching for practical, science-backed solutions. The good news is that a healthy diet for weight loss doesn’t mean extreme restriction or fad trends. By focusing on the best foods for weight loss, like fibre-rich vegetables, lean proteins, and healthy fats, you can reduce abdominal fat, balance your hormones, and build habits that last. In this guide, we’ll explore what really works and how to make weight loss both effective and sustainable.
Obesity is one of the most pressing health challenges of our time. Defined by the World Health Organization as excessive fat accumulation that presents a health risk, obesity is typically diagnosed using Body Mass Index (BMI). A BMI over 25 is considered overweight, and over 30 is considered obese. While BMI doesn’t distinguish between fat and muscle, it remains a useful, non-invasive screening tool.
In South Africa, obesity is becoming alarmingly common. As of 2016, 68% of women and 31% of men were classified as either overweight or obese, with childhood obesity rates also increasing significantly. The rise is especially concerning in our country that also grapples with undernutrition, highlighting a complex public health landscape.
Why Obesity Rates Are Increasing
Several factors contribute to the global and national rise in obesity. Increased sedentary lifestyles, easy access to ultra-processed foods and limited access to nutritious foods make healthy living more difficult.
Ultra-processed foods, especially those high in both fat and refined carbs, may trigger addictive-like responses, similar to drugs. Foods like pizza, chocolate, potato chips, cookies, and ice cream top the list of most “addictive” foods. Natural foods (e.g., apples, beans, brown rice) are much lower in addictive potential. The unnatural combination of fat plus carbs creates an unusually strong reward signal in the brain.
Food additives also disrupt gut health. A Nature study found that food emulsifiers (e.g., polysorbate 80 and carboxymethylcellulose) disrupt gut bacteria in mice. This led to obesity, metabolic syndrome, and inflammatory bowel disease. The gut microbiome plays a key role in weight regulation, and certain additives may tip the balance toward weight gain.
Why Weight Loss Is So Difficult
Contrary to popular belief, losing weight isn't just about willpower. The body has powerful biological mechanisms that resist weight loss and promote weight regain. One of the key concepts here is the weight "set point," an internal thermostat that your body uses to maintain a certain weight range. When you drop below this set point, your body fights back.
Hormones and Metabolic Changes
After weight loss, the hunger hormone ghrelin increases and stays elevated for 1 to 3 years or more, making you constantly preoccupied with food. At the same time, leptin, the hormone that signals fullness, drops. This hormonal imbalance drives cravings, especially for high-fat and sugary foods, and makes weight maintenance feel like an uphill battle.
To make matters worse, your metabolism slows down more than expected. Known as "metabolic adaptation," this slowdown means your body burns fewer calories at rest, even after you've regained the weight. A well-known study of "The Biggest Loser" contestants found that participants had a 500-calorie-per-day slower metabolism even six years after the show.
Fighting Back Against Biology
Although the body fights weight loss, long-term success is still possible. The key is to work with your biology, not against it.
Don’t rely on hunger cues. Elevated ghrelin means you may feel hungry even when you don't need more food. Instead, follow structured meal planning based on logic and nutritional needs.
Eat nutrient-dense foods. Whole, unprocessed foods rich in fibre, protein, and healthy fats are more satisfying and help reduce cravings triggered by hormonal changes.
Build muscle. Resistance training helps counteract metabolic adaptation by increasing resting metabolic rate. Muscle burns more calories than fat, even at rest.
Consider medical support. Obesity is a disease, not a personal failing. Hormonal imbalances and metabolic shifts can make it almost impossible to succeed without support. Medications and even bariatric surgery can be effective tools.
Why Diet Quality Diet for Weight Loss Matters More Than Diet Type
A groundbreaking study published in JAMA found that participants who focused on whole, minimally processed foods, regardless of whether the diet was low-fat or low-carb, lost more weight and improved their overall health. They didn’t count calories or restrict portion sizes. Instead, success was linked to eating vegetables, cooking at home, and cutting back on added sugars and refined grains.
When establishing a healthy diet for weight loss, instead of obsessing over macronutrient ratios, focus on food quality. Avoid hyper-palatable foods that combine fat and sugar (think cakes, chips, and pizza), which hijack the brain’s reward system and promote overeating.
Stress Eating: A Hidden Driver of Weight Gain
Chronic stress is another major barrier to weight loss. Stress increases cortisol levels, which boosts appetite and cravings for comfort foods. These foods dampen the stress response temporarily, reinforcing the habit.
Women are more prone to stress eating, while men may turn to alcohol or smoking. Those with higher baseline cortisol responses are even more vulnerable to weight gain from stress.
How to Beat Stress Eating:
Remove junk food from your environment.
Practice mindfulness and stress-reduction techniques like meditation.
Get regular exercise to regulate cortisol.
Lean on social support when life gets overwhelming.
The Role of Exercise in Weight Loss
While exercise alone doesn't lead to massive weight loss, it's crucial for overall health and weight maintenance.
🔥 Aerobic exercise (like walking, swimming, and cycling) helps burn calories and improves cardiovascular health.
🔥 Resistance training (like weightlifting) is essential for preserving muscle mass and boosting metabolism.
🔥 High-Intensity Interval Training (HIIT) has also shown promise for burning visceral fat and improving metabolic markers. Some studies suggest HIIT may even suppress appetite, making it a useful tool for managing cravings.
The Power of Modest Weight Loss
You don’t need to lose half your body weight to see real health benefits. Losing just 5-10% of your body weight can lead to:
Lower cholesterol and triglycerides
Reduced blood pressure
Improved insulin sensitivity and lower blood sugar levels
Reduced inflammation
Better sleep and decreased need for CPAP in sleep apnea
These modest changes can drastically lower your risk of chronic diseases like type 2 diabetes, heart disease, and stroke.
Key Principles for Sustainable Weight Loss and Long-Term Weight Management
🌿 Avoid extremes. Crash diets and all-or-nothing approaches usually lead to burnout and weight regain. Choose moderate, sustainable changes.
🌿 Enjoy what you eat. Find healthier versions of the foods you love so that you don’t feel deprived.
🌿 Increase vegetable intake. A healthy diet for weight loss includes leafy greens and fibrous vegetables to promote fullness and better health.
🌿 Replace sugary drinks. Opt for water, seltzer, or unsweetened teas.
🌿 Get enough protein. It helps regulate hunger and insulin levels.
🌿 Include healthy fats. Avocados, olive oil, and nuts curb cravings and promote satiety.
🌿 Exercise regularly. Aim for 150 minutes of moderate activity and at least two days of strength training per week.
🌿 Be prepared. Identify trigger situations and plan ahead with healthy snacks.
🌿 Practice portion control. Restaurant servings are often double what we need.
🌿 Try intermittent fasting. It can be as effective as traditional calorie restriction for some people.
Long-term weight loss is hard, but not impossible. The body is wired to regain lost weight, but with the right strategies, you can overcome these challenges. Even small changes can yield big health benefits. Don’t aim for perfection; aim for progress. Your body, and your future self, will thank you.
References: