▎ WuXi AppTec content team editor
The Nutrition and Chronic Disease Status Report of Chinese Residents (2020) states that more than half of adults in China are overweight/obese. And more than 200 diseases are associated with obesity.
Overweight/obesity is preventable, controllable and treatable, with medical nutrition therapy as the basis. In order to solve this major public health problem, the China Overweight/Obesity Medical Nutrition Therapy Expert Consensus Writing Committee has formulated the "Guidelines for The Nutritional Treatment of Overweight/Obesity Medicine in China (2021)", which was recently published in the Chinese Journal of Frontiers in Medicine.
Screenshot source: Chinese Journal of Frontiers in Medicine
The guidelines provide recommendations for important interventions such as diet management, physical activity, and behavioral interventions. In the diet section, special attention was paid to the effect of diet regimens such as high-protein diets, low-carb diets, intermittent fasting, and meal replacement foods on weight loss.
Define goals and find motivation
For the general overweight/obese population, the weight loss target is divided into 5%, 10%, and 15% of the current weight loss, and the weight loss cycle is 3 to 6 months.
Primary target: weight loss ≥5%;
Medium-term goal: weight loss ≥ 10%;
Advanced goal: Weight loss ≥ 15%.
For overweight/obese women with PCOS, a 5% to 10% reduction in initial body weight should be reduced within 6 months. For overweight/obese patients with diabetes, the initial goal should be set at 5% to 10% weight loss.
Image credit: 123RF
Eat and move in balance, and do more with less
Eating the right food and finding a diet pattern that suits you can make weight loss more effective with less. Different weight loss diets have their own characteristics, and the following recommendations are specifically recommended:
01
Limited energy diet
An energy-limited diet is a reduction of 500 kacl to 1000 kcal per day on top of the target energy intake. Males consume 1200 kacl to 1400 kcal of energy per day, and women consume 1000 kacl to 1200 kcal of energy per day, or reduce the recommended intake by 1/3. Among them, carbohydrates account for 55% to 66% of total daily energy, and fat accounts for 25% to 30% of total energy.
Increasing soy protein intake in an energy-restricted diet can reduce body fat rate, serum total cholesterol, and LDL cholesterol levels. Increasing dairy intake in energy-limited diets can reduce body fat levels in overweight/obese patients, while increasing calcium supplements alone does not enhance weight loss.
Under the condition of regular monitoring and close follow-up by a professional team, severely obese people can choose extremely low-energy meal replacement foods (< 800 kcal per day) as a nutritional intervention plan in the short term.
02
High-protein diet
A high-protein diet is defined as a daily protein intake > 1.5 g/kg of body weight, but not more than 2.0 g/kg of body weight.
A high-protein diet helps people with overweight/obese type 2 diabetes lose weight and favors blood sugar control. Clinical monitoring and nutritional counseling, including renal function, should be strengthened for long-term application. A high-protein diet increases satiety, reduces hunger, and helps to increase weight loss adherence and maintain weight loss in severely obese people.
High-protein dietary supplements from sources such as soy protein, whey protein and casein all contribute to weight loss. However, maintaining a high-quality source of protein, mainly dairy products, is more helpful in maintaining bone mass.
For obese people in the elderly (> 65 years old), each meal should contain at least 25 grams to 30 grams of high-quality dietary protein to stimulate muscle protein synthesis.
03
Low carb water diet
A low-carb diet usually refers to a diet in which the energy supply ratio of carbohydrates is ≤ 40%, and the fat energy supply ratio is ≥ 30%.
Short-term low-carbon water diets help control weight and improve metabolism; long-term safety and efficacy need to be further studied.
Overweight/obese type 2 diabetics who adopt a low-carb water diet in the short and medium term can help improve blood sugar control. However, it is not recommended that children and adolescents implement a low-carbohydrate diet for long periods of time for the purpose of weight loss. It can be carried out for a short period of time under the guidance of a clinical dietitian and supplemented with dietary fiber and micronutrients appropriately.
After fully considering safety and trying other weight loss dietary interventions are ineffective, a short-term ketogenic diet (carbohydrate energy supply ratio ≤ 20%) can be carried out under the guidance of a clinical dietitian, but it is necessary to monitor blood ketones, liver and kidney function, body composition changes, blood lipid levels, etc.
04
Intermittent energy limitation
The commonly used intermittent energy limits are the alternate day fasting method, the 5 +2 fasting method (fasting 2 days per week), etc. During the fasting period, the energy supply is usually 0% to 25% of normal demand.
Intermittent energy restriction diets are safe for weight loss in healthy people; intermittent energy restriction diets are also relatively safe for diabetics compared with sustained energy restrictions, but need to be concerned about the adjustment of hypoglycemic drugs.
In overweight/obese patients in non-diabetic patients, intermittent energy-restricted diets improve insulin resistance levels and increase insulin sensitivity, but the effect on blood glucose is unclear.
05
Biorhythms and weight loss
Time limit eating method refers to the restriction of daily eating time, the common fasting time is 4h, 6h, 8h eating 3 types of restrictions, day or night fasting can be a way of eating.
This diet may improve fasting blood glucose, but the effect on insulin resistance and blood lipid metabolism has been inconsistent.
06
Low glycemic index diet
A low glycemic index diet is characterized by low energy, high dietary fiber, which can increase satiety, reduce postprandial blood sugar, increase insulin sensitivity, improve insulin resistance, and also reduce body weight.
07
Multiple dietary patterns
End the hypertensive diet (DASH diet): emphasize increasing the intake of vegetables and fruits, skim milk, whole grains, reduce the intake of red meat, fat, refined sugar and sugary drinks; eat nuts and legumes appropriately. This diet is effective in reducing body weight, BMI and body fat levels in overweight/obese people.
Mediterranean diet: mainly plant-based foods, including whole grains, legumes, vegetables, fruits, nuts, etc.; fish, eggs, dairy products, poultry, and dairy products in moderation; red meat and its products in small amounts; edible oil is mainly olive oil and appropriate consumption of red wine. The Mediterranean diet is effective in reducing weight in people who are overweight/obese, diabetics and metabolic syndromes, and women after childbirth.
Obese patients with metabolic fatty liver disease can choose a dietary pattern such as the Mediterranean diet according to the specific situation during weight loss, but alcohol should be prohibited during weight loss.
Obese gout patients can choose the Mediterranean diet or terminate the hypertensive diet, which not only reduces weight, but also reduces the risk of gout.
08
Meal replacement foods for weight loss
Meal replacement food is a kind of energy control food specially processed and prepared to meet the nutritional needs of one or two meals during the weight control period of adults, instead of partial meals. A meal replacement that meets the criteria needs to be selected, combined with a multivitamin and mineral supplement, to ensure adequate nutrition during weight loss.
Short-term application of meal replacement foods is safe for weight loss, with few serious adverse reactions and good tolerance. Short-term use of meal replacement foods is effective in controlling weight in patients with metabolic syndrome and cardiovascular disease and reducing risk factors for cardiovascular events. But long-term safety needs to be further studied.
09
Exercise weight loss
Overweight and obese individuals should exercise at least 150 minutes of moderate intensity exercise per week to achieve moderate weight loss; if the effect of weight loss ≥5%, the weekly exercise time should reach 300 minutes, and the exercise intensity should be medium-high intensity exercise, or exercise energy consumption of 2000 kcal and above per week.
Aerobic exercise combined with resistance training works best to lose weight. Compared with moderate-intensity continuous exercise, high-intensity intermittent exercise can be used as an effective exercise method for weight loss, fat loss and improvement of cardiopulmonary function, and has the advantage of timeliness.
For individuals with poor adherence, fragmented time can be used to accumulate multiple short-term exercises, and in the case of the same amount of exercise, the weight loss effect is even better than one continuous long-term exercise.
For overweight/obese children and adolescents, high-intensity aerobic exercise is given at least 60 minutes per day, of which at least 3 days per week are high-intensity aerobic exercise, resistance exercise and bone weight-bearing exercise are exercised 2 to 3 times a week.
In addition to dietary and exercise interventions, medical nutrition education and counselling can be provided to all medical weight losers. You can choose mini programs, mobile apps and other ways to conduct online education, provide nutrition and exercise and other suggestions; you can also carry out offline consultation meetings to learn nutrition knowledge and skills. Telemedicine intervention is recommended for at least 6 months and attention should be paid to follow-up after intervention.
Moreover, obese patients should also develop the habit of self-monitoring and change their eating behavior through peer support, motivational interviews, etc. If obese patients are accompanied by mental disorders, especially symptoms such as anxiety, depression and binge eating behavior, psychological treatment should be combined with medical weight loss.
▲Medical nutrition weight loss diagnosis and treatment process of obesity (Source: Reference[1])
Diet and medication, surgery, complement each other
Taking diet pills on the basis of a low-fat diet can significantly reduce weight and reduce fat tissue in the body. At present, the optional weight loss drug in China is orlistat, and its main adverse reactions are gastrointestinal discomfort, such as flatulence, oily stools and so on. If diet + exercise + diet pills are intervened together, further effective weight loss can be achieved. During the recommended period, oral multivitamins, especially vitamin D, are taken daily.
For overweight/obese type 2 diabetics, metformin may be used as a first-line treatment to help with weight loss. Other drugs, such as GLP-1 (glucagon-like peptide 1) receptor agonists and SGLT-2 (sodium-glucose synergistic transporter 2) inhibitors, have had a clear weight loss effect. Dipeptide peptidase 4 (DPP-4) inhibitors and α-glucosidase inhibitors have an inaccurate weight loss effect in the treatment of diabetic patients, and are currently considered to have a neutral effect on body weight.
In addition to diet pills, bariatric surgery is also an efficient method of weight loss. However, all patients who are planning to undergo bariatric surgery should undergo preoperative weight loss by restricting diet. During the perioperative period, nutritional therapy management should be conducted through the entire process of preoperative evaluation, intraoperative monitoring, postoperative rehabilitation, and postoperative follow-up. At the same time, the application of the accelerated rehabilitation surgical concept to perioperative patients may bring additional benefits.
After weight loss, on the basis of maintaining the body's negative energy balance, a sufficient amount of protein and other nutrients should be supplemented, and it is recommended to routinely supplement 350 micrograms to 1000 micrograms of vitamin B12 per day (for patients with pre-existing vitamin B12 deficiency, 1000 micrograms per day and maintenance dose).
If the weight loss effect is not up to standard after weight loss, it is necessary to adjust the dietary structure, increase the protein ratio, and change the behavior of life. If postoperative weight loss is good, it is recommended to follow a restricted energy diet for 3 to 6 months to maintain weight. After the weight reduction, it is more conducive to weight reduction maintenance by participating in the comprehensive weight reduction maintenance plan for ≥ 1 year.
Precision nutrition and supplements to make weight loss more efficient
First, during medical weight loss, an individualized dietary regimen should be used, especially in low-energy dietary interventions, which should be supplemented with both multivitamins and micronutrients to prevent iron deficiency; in addition, weight loss patients at risk of calcium deficiency should be supplemented with calcium and/or vitamin D.
Adult obese people can also help with weight loss by taking probiotics containing specific strains. For patients with non-alcoholic steatohepatitis, Lactobacillus reuteri may be an option to help reduce weight and waist circumference. A combined weight-loss diet of probiotics with Lactobacillus, Bifidobacterium bifidobacterium, and Streptococcus thermophilus improves weight, insulin resistance, and appetite-related hormone levels in patients with metabolic syndrome.
For people who have difficulty meeting weight loss goals with traditional treatment, obesity-related genetic monitoring and corresponding dietary interventions may be considered. For example, diets rich in dietary fiber have a better weight loss effect for people with a high Pepsinus/Bacteroides ratio.
Moderate medium-chain triglyceride supplementation with more than 12 weeks of continuous use may help to reduce weight in overweight/obese patients. A weekly intake of L-Carnitine is 2 to 3 grams, and an intake of more than 8 weeks may help with weight loss. Intake of resistant starch during weight loss may help improve weight and body composition in overweight/obese people, as well as improve blood lipids, blood sugar levels, and insulin sensitivity.
There is a high risk of vitamin D deficiency in overweight/obese women, children, and adolescents. Pregnancy testing should be strengthened during pregnancy. Supplementation with high doses of vitamin D may improve childbirth outcomes. On the basis of vitamin D supplementation, it is recommended to ensure adequate dietary calcium intake in children and adolescents.
For the elderly with less muscular obesity, it is recommended to supplement with 800 to 100 units of vitamin D per day; Ω-3 unsaturated fatty acids can also be supplemented in an appropriate amount.