Will dieting and weight loss affect physical examination results

Dieting to lose weight may have temporary effects on some physical examination indicators, mainly including blood sugar fluctuations, electrolyte imbalances, liver and kidney dysfunction, etc. The key influencing factors include extreme dieting methods, insufficient nutrient intake, decreased metabolic rate, water imbalance, and rapid weight loss rate.

1. Blood sugar fluctuations:

Long term low carbohydrate dieting may lead to low fasting blood sugar and abnormal results in glucose tolerance tests. The body breaks down fat for energy due to a lack of carbohydrates, producing ketone bodies that interfere with metabolic testing. Three days before the physical examination, a balanced diet should be restored to avoid testing errors.

2. Electrolyte imbalance: Excessive restriction of salt and mineral intake can lead to hyponatremia and hypokalemia, affecting the accuracy of electrocardiogram and renal function tests. Manifesting as false positive results such as abnormal creatinine levels and arrhythmia. It is necessary to ensure 1.5 liters of water per day and supplement with foods rich in electrolytes in moderation.

3. Abnormal liver function: When protein intake is insufficient, a decrease in liver synthesis function may lead to a temporary increase in transaminases. The free fatty acids produced by fat breakdown during rapid weight loss can also increase the burden on the liver. Two weeks before the physical examination, the daily protein intake should be at least 1 gram per kilogram of body weight.

4. Decreased metabolic rate:

Long term insufficient calorie intake can cause a 20% -30% decrease in basal metabolic rate, a decrease in thyroid hormone T3 levels, and affect endocrine examination results. This state may last for 4-6 weeks after returning to normal diet, and it is recommended to maintain a stable diet for at least one month before the physical examination.

5. Weight fluctuation interference:

A sudden weight loss of more than 5% in the short term can affect the accuracy of measurement data such as body fat percentage and bone density. The dehydration phenomenon associated with rapid weight loss may lead to blood concentration, resulting in a false increase in red blood cell count and hemoglobin concentration. It is recommended to maintain a stable weight for at least 2 weeks before undergoing a physical examination. Before the physical examination, it is necessary to communicate with the doctor in advance about the recent weight loss situation. Women should pay special attention to the impact of dieting on hormone levels. It is recommended to adopt a gradual weight loss strategy, with a weekly weight loss of no more than 1 kilogram, ensuring a daily calorie intake of over 1200 calories, and prioritizing high protein, high fiber, and low GI foods. Three days before the physical examination, it is necessary to stop any form of extreme diet, fully replenish water and multivitamins, and avoid vigorous exercise. If elevated transaminase levels or electrolyte abnormalities are found, dietary adjustments should be made under the guidance of a nutritionist before re examination. Most indicators can return to normal within 1-2 months. Long term fasting individuals are advised to undergo specialized examinations such as thyroid function and bone density.