From the Guidelines
If an individual maintains a good balanced diet and engages in adequate physical activities but still remains obese, they should consult with a healthcare provider for a comprehensive evaluation to identify potential underlying factors beyond diet and exercise. This situation suggests that the individual's obesity may be influenced by multiple factors, including genetic variants, environmental factors, and potential medical conditions 1. According to the most recent study published in JAMA in 2023, obesity reflects a chronic energy imbalance and is influenced by multiple factors, including genetic variants, adverse environments, and bidirectional associations with depression and other risks 1.
Potential Underlying Factors
Some potential underlying factors that may contribute to obesity despite a healthy diet and regular physical activity include:
- Medical conditions such as hypothyroidism, polycystic ovary syndrome (PCOS), Cushing's syndrome
- Medications like certain antidepressants, antipsychotics, beta-blockers, or corticosteroids
- Genetic factors that influence how the body processes food and stores fat
- Sleep disorders, chronic stress, and age-related metabolic changes
Recommended Course of Action
A healthcare provider can order appropriate tests to check hormone levels, metabolic function, and other potential causes. Treatment may include:
- Addressing any identified medical conditions
- Adjusting medications if possible
- Considering weight management medications like phentermine-topiramate (Qsymia), liraglutide (Saxenda), or semaglutide (Wegovy) in appropriate cases
- Discussing bariatric surgery options in severe cases
- Making small adjustments to diet composition or exercise intensity to help overcome metabolic resistance to weight loss, as suggested by the study published in JAMA in 2023 1.
From the FDA Drug Label
In relatively short-term clinical trials, adult obese subjects instructed in dietary management and treated with “anorectic” drugs lost more weight on the average than those treated with placebo and diet. The individual on a good balanced diet and adequate physical activities who is still obese may benefit from the use of anorectic drugs such as phentermine as it has been shown to result in more weight loss compared to placebo and diet alone. However, the magnitude of increased weight loss is only a fraction of a pound a week. The effectiveness of the drug also decreases over time and other variables such as the physician and population treated may also play a role in the weight loss. 2
- Key points:
- Anorectic drugs may be beneficial for weight loss in obese individuals
- Weight loss is greater with drug treatment compared to placebo and diet alone
- Magnitude of weight loss is limited to a fraction of a pound a week
- Effectiveness of the drug decreases over time
From the Research
Factors Contributing to Obesity
- Despite being on a good balanced diet and engaging in adequate physical activities, an individual may still be obese due to various factors, including genetics and diseases such as hypothyroidism, Cushing's disease, depression, and use of certain medications 3, 4.
- The main cause of obesity is an imbalance between calories consumed and calories expended, although in some cases, genetics and diseases can contribute to fat accumulation in the body 3.
Role of Diet and Exercise in Obesity Management
- Dieting, augmented by physical exercise and supported by cognitive behavioral therapy, is the main treatment for obesity 3.
- A combination of a moderately reduced-calorie diet, increased physical activity, and behavior strategies can produce a modest weight loss of 5% to 10% that can be maintained long term 5.
- Regular physical exercise enhances the efficiency of diet through increased satiating efficiency of a fixed meal and is useful for maintaining diet-induced weight loss 3.
- A systematic review found that a combination of intensive physical activity and a portion-controlled diet led to a more significant weight loss of 5% 6.
Importance of Balanced Dietary Plans
- A balanced dietary plan should have 55% of dietary calories coming from carbohydrates, 10% from proteins, and 30% from fats, with 10% of total fat consisting of saturated fats 3.
- The optimal diet to treat obesity should be safe, efficacious, healthy, and nutritionally adequate, culturally acceptable, and economically affordable, and should ensure long-term compliance and maintenance of weight loss 7.
Genetic and Epigenetic Factors
- Obesity may be considered a heritable trait, with rare cases of monogenic obesity unveiling the importance of hypothalamic circuits and the brain-adipose axis in regulating energy homeostasis, appetite, hunger, and satiety 4.
- Common obesity is linked to genetic predisposition by multiple risk variants, although non-genetic factors such as eating behavior and physical activity strongly modulate the individual risk for developing obesity 4.