Table 3.

Latest evidence in MNT for adult obesity from RCTs and systematic reviews/meta-analyses

First author	Year	Population	Intervention	Duration	Main outcome	Evidence level	Conclusion
RCTs Ghanwat and Sontakke [23]	2019	Adults with WC ≥80/90 cm	Vitamin C 500 mg 3/d	3 months	FBG, insulin, HOMA-IR, and QUICKI	Level 2	Improvement in FBG, insulin, HOMA-IR, and QUICKI
Romain et al. [24]	2021	Adults with BMI 25–40 kg/m2	Flavonoid and vitamin B3-rich extract versus placebo	16 weeks	BW, WC, BF, health-related QoL	Level 2	Improvements in BW, WC, and BF, physical health QoL
Rohling et al. [41]	2021	Adults with BMI 27–35 kg/m2 and w/> 1 component of metabolic syndrome	Meal replacement by formula diet versus lifestyle	52 weeks	BW	Level 2	12 weeks: meal replacement linked to larger BW (-2.39 kg) 52 weeks: no difference
Halle [42]	2020	Adults with BMI 27–35 kg/m2 and w/> 1 component of metabolic syndrome	Meal replacement by formula diet versus lifestyle	52 weeks	FM, FFM, WC, FBG, SBP, DBP, TC, HDL-c, LDL-c, TG	Level 2	Improvements in all parameters
Lowe et al. [53]	2020	Adults with BMI 27–43 kg/m2	Time-restricted eating (16:8 h)	12 weeks	BW, FM, LM, insulin, FBG, HbA1c	Level 2	No evidence of difference
Hassapidou et al. [31]	2020	Adults with BMI ≥25 kg/m2	MED versus usual care	6 months	BW, WC, HC, % BF	Level 2	Weight loss only in the intervention group
Headland et al. [51]	2019	Adults with BMI ≥25 kg/m2	IF versus CER	12 months	BW, body composition, TC, HDL-c, LDL-c, TG, FBG	Level 2	No difference in any parameter
Brown et al. [45]	2020	Adults with T2DM (insulin) and obesity	Low-energy total meal replacement	12 months	BW, HbA1c, FBG, C-peptide, serum lipids, BP, body composition, and QoL	Level 2	Improved BW, HbA1c, insulin dosage, QoL
Gajewska [81]	2019	Adults with BMI ≥25 kg/m2 and hypertension	Nutrition education individual versus group	6 months	BW, WC, BP, FBG, OGTT, HOMA-IR, lipids	Level 2	Better BW, WC, BP, OGTT, HOMA-IR with individual education
Sundfør et al. [52]	2019	Adults with BMI 30–45 kg/m2 and w/> 1 component of metabolic syndrome	IER versus CER	3 months	BW, energy intake	Level 2	No differences in BW Better dietary habits with CER
Cai et al. [32]	2019	Adults >60 y with BMI ≥28 kg/m2	Community intervention versus usual care	24 months	BW, WC, BP, FBG, TC, HDL-c, LDL-c, TG	Level 2	Community intervention linked to improved BW, WC, SBP, TG, HDL-c
Gepner et al. [35]	2019	Adults with WC ≥88/102 cm or TG≥150 mg/dL and HDL-c <40 mg/dL/<50 mg/dL	MED versus low-fat diet	18 months	BW, WC, FBG, insulin, TC, LDL-c, HDL-c, TG, HOMA-IR, hepatic fat content	Level 2	MED reduced hepatic fat content, TG, HDL-c, DBP further than low-fat diet
Mitra [82]	2019	Adults with BMI ≥23 kg/m2	High-protein, vit E, and fibre, energy-restricted diet versus usual care	6 months	BW, WC, HC, FM, FFM, TC, TG, HDL-c, FBG, insulin, CRP, HOMA-IR	Level 2	The intervention led to significant improvements in BW, WC, FM, insulin, HOMA-IR, CRP
Otten [83]	2019	Postmenopausal women with BMI 27–41 kg/m2	Paleolithic dietary pattern versus Nordic diet	2 years	BW, FM, OGTT, Glucagon, GLP-1, GIP	1A large	Paleolithic diet superior to Nordic in BW, FM, and GLP-1
Salas-Salvado et al. [36]	2019	Adults with BMI 27–40 kg/m2 and metabolic syndrome	MED and physical activity weight loss intervention versus MED alone	12 months	BW, WC, FM, FFM, FBG, HOMA-IR, DBP, SBP, HbA1c, TG, TC, HDL-c, CRP, IL, TNF-α	1A large	Intensive MED intervention led to further improvements in BW, WC, insulin, FBG, HOMA-IR, blood lipids
Ilich et al. [25]	2019	Postmenopausal women with 26–45 kg/m2	Calcium (1.5 g/d) and vitamin D (600 IU/d) via foods or supplements	6 months	BW, WC, HC, FM, LM, BMD	Level 2	Calcium and vitamin D supplementation through food associated with better BW and FM
Weaver [84]	2019	Adults >65 y with BMI ≥30 kg/m2	Hypocaloric diet with 1 g/kg BW protein versus normocaloric 0.8 g/kg BW protein	6 months	BW, BMD	1A large	BW changes only in intervention without differences in bone density
Higgins [85]	2019	Adults with BMI ≥25 kg/m2	Sucrose, aspartame, saccharin, sucralose, rebaudioside A	12 weeks	BW, FM, FFM, OGTT	Level 2	Sucrose and saccharin led to increased BW Sucralose associated with BW reduction No impact on OGTT
Phelan et al. [44]	2018	Women at 9–16 weeks gestation with pregestation BMI ≥25 kg/m2	Partial meal replacement versus usual care	26 weeks	Gestational weight gain	Level 2	Partial meal replacement linked with better adherence to gestational weight gain guidelines
Guo et al. [43]	2018	Adults with BMI >24 kg/m2	Meal replacement versus routine diet	12 weeks	BW, WC, HC, FFM, FM, SBP, DBP, TC, TG, HDL-c, FBG	Level 2	Meal replacements were associated with greater improvements in BW, WC, FFM, FM, and FBG
Watson [86]	2018	Adults with BMI ≥25 kg/m2 and T2DM	High-protein versus high-carbohydrate dietary patterns	24 weeks	BW, WC Psychological wellbeing, QoL, sleep	Level 2	High-protein diets expand the positive impact of weight loss on general health and vitality
Madjd [87]	2018	Adult women with overweight or obesity	Replacing low-calorie sweetened beverages with water		Weight loss, BMI, HOMA-IR, 2-h postprandial glucose	Level 2	Replacement of low-calorie sweetened beverages with water after the main meal in women who were regular users of low-calorie sweetened beverages may cause further weight reduction during a 12-month weight maintenance programme. It may also offer benefits in carbohydrate metabolism including improvement of insulin resistance over the long-term weight maintenance period
Gorostegi-Anduaga [88]	2018	Adults with overweight and obesity with primary hypertension and are sedentary	Aerobic exercise and nutritional intervention		Cardiovascular risk scores and vascular age	Level 2	The improvement in CVR factors after 16-week lifestyle changes reduced the risk of suffering a cardiovascular event in adults with overweight/obesity with HTN through the FRS estimation tool but not with the ASCVD score. The risk score algorithms could underestimate CVR in women. In contrast, VA could be a useful and easier tool in the management of individuals with CVRfactors
Kahleova [89]	2018	Adults with overweight or obesity	Plant-based high-carbohydrate, low-fat (vegan) dietary pattern or to maintain their current dietary pattern		A linear regression model was used to test the relationship between carbohydrate intake and body composition and insulin resistance	1A large	Results suggest encouraging a flexible approach to eating behaviour and discouraging rigid adherence to a dietary pattern may lead to better intentional weight loss for older women with overweight and obesity
Berg [90]	2018	Older women with overweight or obesity	Flexible eating behaviour following a diet and exercise intervention		Weight loss	Level 2
Dus-Zuchowska et al. [37]	2018	Postmenopausal women with obesity and a high risk of metabolic syndrome	CED could be an alternative to the MED		CRP and asymmetrical dimethylarginine	Level 2	In the central European postmenopausal women with obesity population, a well-designed, energy-restricted diet with the use of food items traditional for the region (CED) could be a good alternative to MED in terms of AT prevention
Kikuchi [91]	2018	Japanese adults with visceral fat obesity	Refined wheat bread versus whole grain wheat bread		BW, BMI, WC, VFA, lipids, BP, diabetes measures	Level 2	The WW group showed decrease (–4 cm2) in VFA (p < 0.05), whereas the RW group showed no significant changes. These time-dependent changes were significantly different between the groups. WW diet led to significant and safe reductions in VFA in subjects with BMI ≥23 kg/m2. WW diet may contribute to preventing visceral fat obesity
Höchsmann et al. [33]	2021	Adults with obesity	Primary care: ILI		FBG and lipids, SBP, DBP, metabolic syndrome severity	Level 2	A pragmatic ILI consistent with national guidelines and delivered by trained health coaches in primary care produced clinically relevant improvements in cardiometabolic health in an underserved population over 24 months
Miller et al. [29]	2021	Adults 50–75 years old BMI ≥25 kg/m2 with T2DM	Whey protein (40 g/d) + vit D3 (2000 IU/d) combined with exercise versus exercise alone (n = 198)	24 weeks	HbA1c, HOMA2-IR, FBG Body composition, BP, lipid profile, inflammatory markers	Level 2	No effect on body composition, HbA1c, HOMA2-IR Improved FBG
Haghighat [92]	2020	Women with BMI between 18.5 and 24.9 kg/m2 and an excess in BF% >33.3%	Euengetic high protein versus standard protein		Appetite and body composition	1A large
Aparecida Silveira [93]	2020	Adults with sarcopenia and severe obesity	EVOO and/or the traditional Brazilian diet			Level 2	DieTBra contributes to improvements in handgrip strength, walking speed, and total BF in adults with obesity (BMI >40 kg/m2)
Lison [94]	2020	Patients with obesity and hypertension	Web-based exercise and nutritional education		BMI (primary outcome), FM, SBP, DBP, FBG, insulin, physical activity levels, and functional capacity for aerobic exercise	Level 2
Rakvaag et al. [30]	2019	Adults with abdominal obesity (n = 65)	Whey protein (60 g/d) combined with wheat bran (30 g/d)	12 weeks	Fasting and postprandial lipid profiles	1A large	Whey protein increased fasting TC with or without wheat bran Whey protein improved TG only without wheat bran
Yari [95]	2020	Adults with overweight or obesity	Flaxseed		Anthropometric measurements, lipid profile, HOMA-IR, and inflammatory biomarkers	Level 2
Meta-analysis or systematic review of high-quality RCT
Qu et al. [28]	2021	Adults BMI ≥25 kg/m2	Prebiotics supplements versus Placebo		BMI, BW, WC CRP, TN-a, IL-1β, LPS	Level 1a (meta-analysis)	No difference in adiposity parameters Improvements in inflammatory markets
Enriquez Guerrero [96]	2021	Adult population (18–70 years old) with BMI ≥25 kg/ m2	IF versus CER		BMI, BW, WC, FM TC, HDL-c, LDL-c, TG	Level 1a (meta-analysis)	IF showed higher weight loss and higher FM reduction but similar WC reduction IF improved lipid profile, but evidence is less conclusive
Willems [97]	2021	Adults with obesity	Low-carbohydrate and low-fat dietary patterns		Markers of the metabolic syndrome	Level 2	Higher fat and protein intakes associated with improved markers of MetS
Park et al. [46]	2020	Adults BMI ≥25 kg/m2	ADF		BMI, BW, WC, FM, and LM TC, TG, HDL-c, LDL-c, FBG, insulin, HOMA-IR, CRP, SBP, and DBP	Level 1a	ADF effectively lowers BMI, BW, FM, and TC in adults with BMI ≥25–29.9 kg/m2 in interventions <6 months compared to control ADF lowers WC in adults with BMI ≥30 kg/m2, ≥40 years old
Yan et al. [47]	2020	Adults with overweight or obesity	Fasting		BW, BMI, FFM, FM, WC, TC, LDL-c, HDL-c, TG, SBP, DBP, FBG, insulin	Level 1a	Our meta-analysis found that fasting was associated with a significant effect on the regulation of anthropometric (BW, BMI, FEM, FM, and WC) and metabolic parameters (LDL-C, TG, SBP, and DBP) in people with overweight or obesity
Maula et al. [39]	2020	Adults with overweight or obesity and type 2 diabetes	Educational weight loss interventions		BW and BMI change	Level 1a	Low-calorie, low-carbohydrate meal replacements or dietary patterns combined with education appear the most promising interventions to achieve the largest weight and BMI reductions in people with type 2 diabetes
Wang [98]	2020	Adults with overweight or obesity	Whole grain foods		Cardiovascular risk outcomes	Level 1a	This study suggests that whole grain food consumption can slightly reduce BW and CRP in people with overweight/obesity
Mu [99]	2019	Asian women (non-menopausal) with overweight or obesity	Soy products		BW, BMI, % BF, FM, WC	Level 1a	This meta-analysis showed that soy products have weight loss effects, mainly due to soy protein, isoflavone, and soy fibre
Suzumura et al. [27]	2019	Adults with overweight or obesity		Oral supplementation with probiotics or symbiotics	BW, BMI, WC	Level 1a	oral supplementation with probiotics or symbiotics has a small effect on WC reduction but no effect on BW or BMI Low to moderate quality of evidence
Roman et al. [50]	2019	Adults with overweight or obesity	Intermittent versus continuous fasting		BW, BF, LM, WC, HC, and energy expenditure (kJ/day)	Level 1a	This systematic review in individuals with overweight and obesity showed that regular IF decreased LM compared to continuous fasting. There were no differences in effects for either intermittent versus continuous interventions across all other outcomes
Bassatne et al. [26]	2019	Adults with obesity	Vitamin D supplementation		BMD, extra-skeletal parameters	Level 2	No clear evidence for a beneficial effect of vitamin D supplementation on cardiometabolic parameters in adults living with obesity
Gjuladin-Hellon [100]	2019	Adults BMI ≥25 kg/m2	Very low- and low-carbohydrate dietary patterns versus low-fat dietary patterns		TC, TG, HDL-c, LDL-c	Level 1a (meta-analysis)	Carbohydrate restriction is superior to fat restriction in improving lipid profile
Astbury et al. [40]	2019	Adults with overweight or obesity	Meal replacements		Weight loss	Level 1a	Programmes incorporating meal replacements led to greater weight loss at 1 year than comparator weight loss programmes and should be considered as a valid option for management of overweight and obesity in community and healthcare settings
Booth [101]	2018	Adults with overweight or obesity	Diet-induced weight loss		Psychological stress	Level 1a
Castellana [102]	2020	Adults with overweight or obesity	VLCKD		BW, BMI, WC, body composition, BP, HbA1c, lipids, and markers of liver and kidney function	Level 1a	VLCKD proved to be a reliable option to achieve a significant weight loss in patients with overweight and obesity. Results were early obtained during the ketogenic phase and were stable over a follow-up of up to two years. In addition, VLCKD was associated with significant improvements in comorbidities, including hypertension, dyslipidaemia, T2DM, and NAFLD. However, an increase in serum sodium was found. VLCKD should thus be regarded as an effective intervention to be proposed to properly selected patients, as a part of a multicomponent strategy, and under strict medical supervision
Noronha et al. [38]	2019	Adults with overweight or obesity and T2D	Liquid meal replacements		Cardiometabolic risk factors	Level 1a	Liquid meal replacements in weight loss diets lead to modest reductions in BW, BMI, and SBP and reductions of marginal clinical significance in BF, WC, HbA1c, fasting glucose, fasting insulin, and DBP
Cheng [103]	2018	Postmenopausal women with obesity	Nutrition and exercise interventions		BW, BMI, WC, FM, LM	Level 1a (meta-analysis)	Diet and exercise combined results in greater weight loss, FM, and LM loss Diet alone leads to greater weight loss than exercise alone
Jovanovski [104]	2021	Adults BMI ≥25 kg/m2	Viscous fibre supplementation in calorie-restricted dietary pattern		BW, BMI, WC, BF	Level 1a (meta-analysis)	Moderate evidence for reduced BW, BMI, and BF Low evidence for reduced WC
Vitale and Kim [49]	2020	Adults with obesity and T2DM	IF		BW and glycaemic control	Level 1a (systematic review)	Insignificant differences between IF and CER on glycated haemoglobin A1c and body composition
Canuto et al. [34]	2021	Adults with overweight and obesity	Primary care interventions		Weight reduction	Level 3 (meta-analysis)	No impact of diet alone or combined approaches on weight loss Similar findings for individual versus group sessions
Churuangsuk [105]	2018	Adults with overweight or obesity	Low-carb dietary patterns		Weight loss	Level 3 (review of reviews)	Little or no difference in weight loss with low-carb dietary patterns versus control

TD2M, type 2 diabetes mellitus; BMI, body mass index; WC, waist circumference; HC, hip circumference; BF, body fat; BW, body weight; FM, fat mass; LM, lean mass; FFM, fat free mass; TC, total cholesterol; HDL-c, high-density lipoprotein cholesterol; LDL-c, low-density lipoprotein cholesterol; TG, triglyceride; CRP, C-reactive protein; TN-a, tumour necrosis factor alpha; IL-1β, interleukin 1β; LPS, lipopolysaccharide; BP, blood pressure; SBP, systolic blood pressure; DBP, diastolic blood pressure; FBG, fasting blood glucose; HOMA-IR, homeostatic model assessment for insulin resistance; HbA1c, glycated haemoglobin; OGTT, oral glucose tolerance test; BMD, bone mineral density; ILI, intensive lifestyle intervention; EVOO, extra virgin olive oil; IER, intermittent energy restriction; CED, Central European diet; VFA, visceral fat area. ADF, alternate day fasting; VLCKD, very low-calorie ketogenic diet.