Protein adequacy, plant protein proportion and main plant protein sources consumed across vegan, vegetarian, pesco-vegetarian and semi-vegetarian diets: A systematic review.

BACKGROUND: There are several types of plant-based diets, with unknown differences across diets on total/plant protein intake and variety of plant protein sources consumed. OBJECTIVE: This systematic review compares total protein intake, proportion of plant proteins and main plant-protein sources consumed across four primarily plant-based diets: vegan, vegetarian, pesco-vegetarian and semi-vegetarian. METHODS: We included observational studies reporting on protein intake and/or protein sources in generally healthy adults that were published between 2002 and 2023. We determined (i) % energy from total and plant protein, (ii) the proportion of plant protein relative to total protein intake and (iii) main plant protein sources (median % contribution of each source to total plant protein intake; interquartile range) consumed across the four diets. The plant protein sources were broadly classified into United States Department of Agriculture (USDA) food-groups: "grains", "nuts and seeds", "soy-products" and "beans, peas, lentils". RESULTS: We included 13 studies reporting on protein intake/sources that were conducted in the US, Europe, and South Korea. Of these, 7 reported on vegan, 11 on vegetarian, 7 on pesco-vegetarian and 7 on semi-vegetarian diets with total protein intake ranging from 10-17.4%. Vegan diets had the highest plant protein proportion (ranging from 77-98%) and semi-vegetarian diets the lowest (ranging from 37-83%). Plant protein source contribution was highest from grains (ranging from 60-78%). Nuts and seeds were most consumed in vegetarian diets (7.9%;2.9-10.3%) and least in semi-vegetarian diets (3.7%;2-14.8%). Soy products, beans, peas, and lentils were most consumed in vegan diets (17.3%;16.3-19.9 and 19.6%;14.6-21.3, respectively) and least in semi-vegetarian (3.7%;1.3-13.9 and 8.5%;5.2-10.2) diets. CONCLUSIONS: Vegan diets had the highest plant protein proportion and a variety of plant protein sources, while semi-vegetarian diets had the lowest plant protein proportion and mainly relied on grains as a plant protein source.

New metrics of dietary carbohydrate quality.

PURPOSE OF REVIEW: The aim of this study was to introduce novel metrics of dietary carbohydrates quality relevant for products and diets. RECENT FINDINGS: Carbohydrate quality has long been associated with a low glycemic index. More recently, novel metrics of carbohydrate quality featuring variations of total carbohydrates-fibers-free sugars ratios have been applied to carbohydrate-rich foods, including grains, beans, vegetables, and fruit. High scoring products had higher levels of health-promoting nutrients (protein, dietary fiber, iron, magnesium, zinc, potassium, selenium, and various B-vitamins) and lower levels of nutrients of public health concern (total sugar, added/free sugars, and fat profile). Cross-sectional studies also found variants of carbohydrate quality metrics to be associated with better markers of cardiometabolic disease, including lower levels of blood triglycerides:high-density lipoprotein cholesterol ratio, homeostatic model assessment of insulin resistance, and SBP. SUMMARY: New ratio-based carbohydrate quality metrics are built around high fiber and whole grain content, combined with a low free sugar content. Such metrics allow the identification of food products of higher overall nutritional quality, and are associated with improved diet quality and certain health outcomes.

Measures of carbohydrate quality and their association with diet quality and cardiometabolic health outcomes in Singapore middle-aged and older adults.

BACKGROUND AND AIMS: Carbohydrate quality may play a key role in cardiometabolic health and disease risk. This study aimed to assess the dietary carbohydrate quality of the free-living middle-aged and older adults in Singapore, and its association with overall diet quality and cardiometabolic health. METHODS AND RESULTS: This cross-sectional study examined the diet and cardiometabolic disease risk indicators of middle-aged and older adults in Singapore (n = 104). Dietary carbohydrate quality was assessed as the pass and fail rate of the population to four measures of carbohydrate quality: (i) dietary fiber recommended daily allowance (RDA), (ii) whole-grain recommendation, (iii) free sugar recommendation, and (iv) carbohydrate metrics. The association between each carbohydrate quality measure and diet quality, as well as cardiometabolic health, was assessed. Except for free sugar recommendation, the carbohydrate quality of the population was found to be poor with a low adherence (20-36%) to three measures. Subjects meeting these measures had generally higher intakes of fiber, protein, and most micronutrients compared with subjects who failed. Meeting different variants of the carbohydrate metrics was associated with 60% lower odds of pre-hypertensive blood pressure (p = 0.037; p = 0.047), and meeting the dietary fiber RDA was associated with lower waist circumference (p = 0.021). CONCLUSION: An improvement in carbohydrate quality is warranted among free-living middle-aged and older adults in Singapore. Not all measures of carbohydrate quality were equally effective in preserving overall diet quality; the carbohydrate metrics and dietary fiber RDA can be identified as effective measures in relation to cardiometabolic disease risk. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ CLINICAL TRIAL REGISTRATION: NCT03554954, 13 Sept. 2018.

Importance of Carbohydrate Quality: What Does It Mean and How to Measure It?

Dietary carbohydrates are our main source of energy. Traditionally, they are classified based on the polymer length between simple and complex carbohydrates, which does not necessarily reflect their impact on health. Simple sugars, such as fructose, glucose, and lactose, despite having a similar energy efficiency and caloric content, have very distinct metabolic effects, leading to increased risk for various chronic diseases when consumed in excess. In addition, beyond the absolute amount of carbohydrate consumed, recent data point out that the food form or processing level can modulate both the energy efficiency and the cardiometabolic risk associated with specific carbohydrates. To account for both of these aspects-the quality of carbohydrates as well as its food form-several metrics can be proposed to help identifying carbohydrate-rich food sources and distinguish between those that would favor the development of chronic diseases and those that may contribute to prevent these. This review summarizes the findings presented during the American Society of Nutrition Satellite symposium on carbohydrate quality, in which these different aspects were presented.

The scientific basis for healthful carbohydrate profile.

Dietary guidelines indicate that complex carbohydrates should provide around half of the calories in a balanced diet, while sugars (i.e., simple carbohydrates) should be limited to no more than 5-10% of total energy intake. To achieve this public health goal a collective effort from different entities including governments, food & beverage industries and consumers is required. Some food companies have committed to continually reduce sugars in their products. Different solutions can be used to replace sugars in food products but it is important to ensure that these solutions are more healthful than the sugars they replace. The objectives of this paper are, (1) to identify carbohydrates and carbohydrates sources to promote and those to limit for dietary intake and food product development, based on current knowledge about the impact of carbohydrates on the development of dental caries, obesity and cardio-metabolic disorders (2) to evaluate the impact of food processing on the quality of carbohydrates and (3) to highlight the challenges of developing healthier products due to the limitations and gaps in food regulations, science & technology and consumer education.

Impact of Cereal Seed Sprouting on Its Nutritional and Technological Properties: A Critical Review.

Sprouting induces activation and de novo synthesis of hydrolytic enzymes that make nutrients available for plant growth and development. Consumption of sprouted grains is suggested to be beneficial for human health. Positive consumer perceptions about sprouted cereals have resulted in new food and beverage product launches. However, because there is no generally accepted definition of "sprouting," it is unclear when grains are to be called sprouted. Moreover, guidelines about how much sprouted grain material food products should contain to exert health benefits are currently lacking. Accordingly, there is no regulatory base to develop appropriate food labeling for "sprouted foods." This review describes the nutritional and technological properties of sprouted grains in relation to processing conditions and provides guidelines to optimize sprouting practices in order to maximize nutritive value. Relatively long sprouting times (3 to 5 days) and/or high processing temperatures (25 to 35 °C) are needed to maximize the de novo synthesis and/or release of plant bioactive compounds. Nutrient compositional changes resulting from sprouting are often associated with health benefits. However, supportive data from clinical studies are very scarce, and at present it is impossible to draw any conclusion on health benefits of sprouted cereals. Finally, grains sprouted under the above-mentioned conditions are generally unfit for use in traditional food processing and it is challenging to use sprouted grains as ingredients without compromising their nutrient content. The present review provides a basis for better defining what "sprouting" is, and to help further research and development efforts in this field as well as future food regulations development.

Metabolic effects of fructose and the worldwide increase in obesity.

While virtually absent in our diet a few hundred years ago, fructose has now become a major constituent of our modern diet. Our main sources of fructose are sucrose from beet or cane, high fructose corn syrup, fruits, and honey. Fructose has the same chemical formula as glucose (C(6)H(12)O(6)), but its metabolism differs markedly from that of glucose due to its almost complete hepatic extraction and rapid hepatic conversion into glucose, glycogen, lactate, and fat. Fructose was initially thought to be advisable for patients with diabetes due to its low glycemic index. However, chronically high consumption of fructose in rodents leads to hepatic and extrahepatic insulin resistance, obesity, type 2 diabetes mellitus, and high blood pressure. The evidence is less compelling in humans, but high fructose intake has indeed been shown to cause dyslipidemia and to impair hepatic insulin sensitivity. Hepatic de novo lipogenesis and lipotoxicity, oxidative stress, and hyperuricemia have all been proposed as mechanisms responsible for these adverse metabolic effects of fructose. Although there is compelling evidence that very high fructose intake can have deleterious metabolic effects in humans as in rodents, the role of fructose in the development of the current epidemic of metabolic disorders remains controversial. Epidemiological studies show growing evidence that consumption of sweetened beverages (containing either sucrose or a mixture of glucose and fructose) is associated with a high energy intake, increased body weight, and the occurrence of metabolic and cardiovascular disorders. There is, however, no unequivocal evidence that fructose intake at moderate doses is directly related with adverse metabolic effects. There has also been much concern that consumption of free fructose, as provided in high fructose corn syrup, may cause more adverse effects than consumption of fructose consumed with sucrose. There is, however, no direct evidence for more serious metabolic consequences of high fructose corn syrup versus sucrose consumption.

Sugar replacers: from technological challenges to consequences on health.

PURPOSE OF REVIEW: Dietary sugars play a role in noncommunicable diseases and represent a clear target for reduction. In this context, product reformulation can have a positive impact on health. Several technological solutions are available to replace sugar, all with benefits and limitations. The goal of this review is to describe the main sugar replacement alternatives and discuss their impact on health and product physicochemical properties. RECENT FINDINGS: Although high intensity sweeteners and polyols have been used for a long time to replace sucrose and despite no clear evidence of harm, the trend is today to look for alternatives such as sweet enhancers or alternative sugars such as allulose or tagatose, which are both low caloric. To replace the physical properties of sugars, new trends are to substitute widely used maltodextrins by dietary fibres to confer added health benefits. SUMMARY: A wide range of solutions is currently available to replace dietary sugars and compensate for the impact on bulking properties and sweetness profile of food products.

Health effects of fructose and fructose-containing caloric sweeteners: where do we stand 10 years after the initial whistle blowings?

Suspicion that fructose-containing caloric sweeteners (FCCS) may play a causal role in the development of metabolic diseases has elicited intense basic and clinical research over the past 10 years. Prospective cohort studies converge to indicate that FCCS, and more specifically sugar-sweetened beverages (SSBs), consumption is associated with weight gain over time. Intervention studies in which FCCS or SSB consumption is altered while food intake is otherwise left ad libitum indicate that increased FCCS generally increases total energy intake and body weight, while FCCS reduction decreases body weight gain. Clinical trials assessing the effects of SSB reduction as a sole intervention however fail to observe clinically significant weight loss. Many mechanistic studies indicate that excess FCCS can cause potential adverse metabolic effects. Whether this is associated with a long-term risk remains unknown. Scientific evidence that excess FCCS intake causes more deleterious effects to health than excess of other macronutrients is presently lacking. However, the large consumption of FCCS in the population makes it one out of several targets for the treatment and prevention of metabolic diseases.

A meta-analysis comparing the effectiveness of alternate day fasting, the 5:2 diet, and time-restricted eating for weight loss.

OBJECTIVE: The objective of this meta-analysis was to compare the effectiveness of different intermittent fasting (IF) regimens on weight loss, in the general population, and compare these to traditional caloric energy restriction (CER). METHODS: Three databases were searched from 2011 to June 2021 for randomized controlled trials (RCTs) that assessed weight loss and IF, including alternate day fasting (ADF), the 5:2 diet, and time-restricted eating (TRE). A random effect network analysis was used to compare the effectiveness between the three regimens. Meta-regression analysis was presented as weighted mean differences of body weight loss. RESULTS: The exploratory random effects network analysis of 24 RCTs (n = 1768) ranked ADF as the most effective, followed by CER and TRE. The meta-analysis showed that IF regimens resulted in similar weight loss to CER (mean difference 0.26 kg, 95% CI: -0.31 to 0.84; p = 0.37). Compliance was generally high (>80%) in trials shorter than 3 months. CONCLUSIONS: The present meta-analysis concludes that IF is comparable to CER and a promising alternative for weight loss. Among the three regimens, ADF showed the highest effectiveness for weight loss, followed by CER and TRE. Further well-powered RCTs with longer durations of intervention are required to draw solid conclusions.

High rates of fructose malabsorption are associated with reduced liver fat in obese African Americans.

OBJECTIVE: African Americans commonly have lower liver fat accumulation than Hispanics, despite a similar propensity for obesity. Both ethnicities exhibit high consumption of fructose-containing beverages, which has been associated with high liver fat owing to the lipogenic properties of fructose. Therefore, differences in fructose absorption may be an important factor in regulating liver fat deposition. We hypothesized that fructose malabsorption in African Americans may reduce hepatic delivery of fructose, thus contributing to lower liver fat deposition compared to Hispanics. METHODS: Thirty-seven obese young adults aged 21.4 ± 2.1 years (16 African American, 21 Hispanic) underwent a 3-hour hydrogen (H2) breath test to assess fructose malabsorption. Magnetic resonance imaging was used to determine visceral and subcutaneous adipose tissue volume and liver fat. Fructose malabsorption was expressed as an area under the curve for H2 production (H2 AUC). RESULTS: Compared to Hispanics, African Americans had lower liver fat (5.4% ± 5.0% vs 8.9% ± 2.3%, p = 0.02) and a higher prevalence of fructose malabsorption (75.0% vs 42.9%; p = 0.05). Liver fat was negatively related to the extent of fructose malabsorption in African Americans (r = -0.53, p = 0.03), and this relationship was independent of the volumes of total fat and subcutaneous and visceral adipose tissue. There were no significant relationships between liver fat and fructose malabsorption in Hispanics. CONCLUSION: African Americans have both a higher prevalence and a greater magnitude of fructose malabsorption than Hispanics. In African Americans, fructose malabsorption was negatively correlated with liver fat, which may be protective against fatty liver disease.

Micronutrient Profile and Carbohydrate Microstructure of Commercially Prepared and Home Prepared Infant Fruit and Vegetable Purees.

Large variability exists in ingredient selection and preparation of home prepared infant purees and there is a lack of data on nutritional quality in comparison to commercially prepared purees. This work had two aims. Study 1 compared the nutritional value of commercially prepared and home prepared infant purees. Food profiles from national food composition databases were used as a proxy for home prepared puree and served as the benchmark for the commercially prepared infant purees. Study 2 focused on a subset of produce that underwent molecular weight analysis to determine differences in carbohydrate profiles. Eighty-eight percent of the measurable micronutrients fell within or above the home prepared norm range with micronutrients falling below the range explained by differences in soil and growing conditions. Physicochemical characterization showed similar carbohydrate profiles with >90% of the carbohydrate fraction in the water extract constituted by low molecular weight sugars for purees produced with home preparation and commercial preparation. The estimated glycemic load (eGL) showed comparable potential impact on blood sugar levels with all purees having a low eGL (<10 glucose equivalent). In conclusion, these data suggest that both preparations provide similar micronutrient density and carbohydrate profiles.

Balanced carbohydrate ratios are associated with improved diet quality in Australia: A nationally representative cross-sectional study.

BACKGROUND: Carbohydrate quality influences major health outcomes; however, the best criteria to assess carbohydrate quality remain unknown. OBJECTIVE: The objectives were to: i) evaluate whether a diet that meets a carbohydrate ratio (simple, modified or dual ratio) is associated with higher nutrient intakes and diet quality, and ii) model the impact of substituting carbohydrate foods that meet the proposed ratios in place of foods that do not, on nutrient intakes. DESIGN: A secondary analysis of cross-sectional data from the 2011-12 Australian National Nutrition and Physical Activity Survey. PARTICIPANTS/SETTING: National data from participants aged 2 years and older (n = 12,153). MAIN OUTCOME MEASURES: Ratios were defined as (i) simple ratio, 10:1 (10g carbohydrate:≥1g dietary fiber); (ii) modified ratio, 10:1:2 (10g carbohydrate:≥1g dietary fiber:≤2g free sugars); and (iii) dual ratio, 10:1 & 1:2 (10g carbohydrate:≥1g dietary fiber & ≤2g free sugars per 1g dietary fiber). Ratios were compared to nutrient intakes obtained via automated multiple-pass 24-hour dietary recall and diet quality calculated using the Australian Healthy Eating Index. STATISTICAL ANALYSES PERFORMED: Substitution dietary modelling was performed. Data were analyzed using paired and independent sample t-tests. RESULTS: Ratio adherence was highest for simple (50.2% adults; 28.6% children), followed by dual (40.6% adults; 21.7% children), then modified (32.7% adults; 18.6% children) ratios. Participants who met any ratio reported higher nutrient intake and diet quality compared to those who failed to meet the respective ratio (P < .001 for all), with the greatest nutrient intakes found for those who met modified or dual ratios. Dietary modelling improved nutrient intakes for all ratios, with the greatest improvement found for the dual ratio. CONCLUSIONS: All carbohydrate ratios were associated with higher diet quality, with a free sugars constraint in the dual ratio providing the greatest improvements.

Effects of a short-term overfeeding with fructose or glucose in healthy young males.

Consumption of simple carbohydrates has markedly increased over the past decades, and may be involved in the increased prevalence in metabolic diseases. Whether an increased intake of fructose is specifically related to a dysregulation of glucose and lipid metabolism remains controversial. We therefore compared the effects of hypercaloric diets enriched with fructose (HFrD) or glucose (HGlcD) in healthy men. Eleven subjects were studied in a randomised order after 7 d of the following diets: (1) weight maintenance, control diet; (2) HFrD (3.5 g fructose/kg fat-free mass (ffm) per d, +35 % energy intake); (3) HGlcD (3.5 g glucose/kg ffm per d, +35 % energy intake). Fasting hepatic glucose output (HGO) was measured with 6,6-2H2-glucose. Intrahepatocellular lipids (IHCL) and intramyocellular lipids (IMCL) were measured by 1H magnetic resonance spectroscopy. Both fructose and glucose increased fasting VLDL-TAG (HFrD: +59 %, P < 0.05; HGlcD: +31 %, P = 0.11) and IHCL (HFrD: +52 %, P < 0.05; HGlcD: +58 %, P = 0.06). HGO increased after both diets (HFrD: +5 %, P < 0.05; HGlcD: +5 %, P = 0.05). No change was observed in fasting glycaemia, insulin and alanine aminotransferase concentrations. IMCL increased significantly only after the HGlcD (HFrD: +24 %, NS; HGlcD: +59 %, P < 0.05). IHCL and VLDL-TAG were not different between hypercaloric HFrD and HGlcD, but were increased compared to values observed with a weight maintenance diet. However, glucose led to a higher increase in IMCL than fructose.

Sex differences in lipid and glucose kinetics after ingestion of an acute oral fructose load.

The increase in VLDL TAG concentration after ingestion of a high-fructose diet is more pronounced in men than in pre-menopausal women. We hypothesised that this may be due to a lower fructose-induced stimulation of de novo lipogenesis (DNL) in pre-menopausal women. To evaluate this hypothesis, nine healthy male and nine healthy female subjects were studied after ingestion of oral loads of fructose enriched with 13C6 fructose. Incorporation of 13C into breath CO2, plasma glucose and plasma VLDL palmitate was monitored to evaluate total fructose oxidation, gluconeogenesis and hepatic DNL, respectively. Substrate oxidation was assessed by indirect calorimetry. After 13C fructose ingestion, 44.0 (sd 3.2)% of labelled carbons were recovered in plasma glucose in males v. 41.9 (sd 2.3)% in females (NS), and 42.9 (sd 3.7)% of labelled carbons were recovered in breath CO2 in males v. 43.0 (sd 4.5)% in females (NS), indicating similar gluconeogenesis from fructose and total fructose oxidation in males and females. The area under the curve for 13C VLDL palmitate tracer-to-tracee ratio was four times lower in females (P < 0.05), indicating a lower DNL. Furthermore, lipid oxidation was significantly suppressed in males (by 16.4 (sd 5.2), P < 0.05), but it was not suppressed in females ( -1.3 (sd 4.7)%). These results support the hypothesis that females may be protected against fructose-induced hypertriglyceridaemia because of a lower stimulation of DNL and a lower suppression of lipid oxidation.

An Assessment of Three Carbohydrate Metrics of Nutritional Quality for Packaged Foods and Beverages in Australia and Southeast Asia.

Carbohydrate quality is an aetiological factor of diet-related disease. Indices of carbohydrate quality featuring various ratios of carbohydrates-to-dietary fibre-to-sugar have been associated with improved product and/or diet quality in westernised countries. Carbohydrate intake is especially high in Asia Pacific. Thus, this study evaluated the ability of such carbohydrate metrics to discriminate the nutritional quality of carbohydrate-rich packaged foods and beverages in Australia, Malaysia, Singapore, Thailand and the Philippines, with an additional focus on beverages. This evaluation was conducted by comparing product nutritional composition and assessing products against three national nutrient profiling models. Results showed that Australia had the highest proportion of products meeting all metrics, compared to the Southeast Asian countries. Beverages had a low adherence to all metrics compared to solid foods. Across the five countries, both processed food and beverages meeting the metrics generally contained higher dietary fibre, protein, and certain vitamins and minerals whilst having lower energy, total sugars, free sugars, trans fat and cholesterol content compared to products not meeting the metrics. The metrics were also aligned with national nutrient profiling models to identify nutritious products. In conclusion, these metrics allowed us to discriminate product nutritional quality in the countries assessed and are applicable to beverages.

Cereal B-Glucans: The Impact of Processing and How It Affects Physiological Responses.

Cereal ß-glucans are dietary fibres primarily found in oats and barley, and have several positive effects on health, including lowering the postprandial glucose response and the improvement of blood cholesterol levels. Cereal ß-glucans have a specific combination of ß-(1→4) and ß-(1→3) linkages into linear long-chain polysaccharides of high molecular weight. Due to their particular structure, cereal ß-glucans generate viscosity within the intestinal tract, which is thought to be the main mechanism of action responsible for their positive health effects. However, cereal grains are rarely consumed raw; at least one cooking step is generally required before they can be safely eaten. Cooking and processing methods more generally will modify the physicochemical characteristics of ß-glucans, such as molecular weight, extractability and the resulting viscosity. Therefore, the health impact of ß-glucans will depend not only on the dose administered, but also on the ways they are processed or converted into food products. This review aims at summarizing the different parameters that can affect ß-glucans efficacy to improve glucose and lipid metabolism in humans.

Predicting Glycemic Index and Glycemic Load from Macronutrients to Accelerate Development of Foods and Beverages with Lower Glucose Responses.

Low glycemic index (GI) and/or low glycemic load (GL) are associated with decreased risks of type-2 diabetes and cardiovascular disease. It is therefore relevant to consider GI and GL in the early phases of the development of packaged foods and beverages. This paper proposes a model that predicts GI and GL from macronutrient composition, by quantifying both the impact of glycemic carbohydrates and the GI-lowering effects of nutrients such as proteins, fats and fibers. The precision of the model is illustrated using data on 42 breakfast cereals. The predictions of GI (r = 0.90, median residual = 2.0) and GL (r = 0.96, median residual = 0.40 g) compete well with the precision of the underlying in-vivo data (Standard Error SE = 3.5 for GI). This model can guide product development towards lowering GI and GL, before final confirmation by in vivo testing.

A high-fructose diet impairs basal and stress-mediated lipid metabolism in healthy male subjects.

The effects of a 7 d high-fructose diet (HFrD) or control diet on lipid metabolism were studied in a group of six healthy lean males. Plasma NEFA and beta-hydroxybutyrate concentrations, net lipid oxidation (indirect calorimetry) and exogenous lipid oxidation (13CO2 production) were monitored in basal conditions, after lipid loading (olive oil labelled with [13C]triolein) and during a standardised mental stress. Lactate clearance and the metabolic effects of an exogenous lactate infusion were also monitored. The HFrD lowered plasma concentrations of NEFA and beta-hydroxybutyrate as well as lipid oxidation in both basal and after lipid-loading conditions. In addition, the HFrD blunted the increase in plasma NEFA and exogenous lipid oxidation during mental stress. The HFrD also increased basal lactate concentrations by 31.8 %, and lactate production by 53.8 %, while lactate clearance remained unchanged. Lactate infusion lowered plasma NEFA with the control diet, and net lipid oxidation with both the HFrD and control diet. These results indicate that a 7 d HFrD markedly inhibits lipolysis and lipid oxidation. The HFrD also increases lactate production, and the ensuing increased lactate utilisation may contribute to suppress lipid oxidation.

What is the appropriate upper limit for added sugars consumption?

Dramatic increases in obesity and diabetes have occurred worldwide over the past 30 years. Some investigators have suggested that these increases may be due, in part, to increased added sugars consumption. Several scientific organizations, including the World Health Organization, the Scientific Advisory Council on Nutrition, the Dietary Guidelines Advisory Committee 2015, and the American Heart Association, have recommended significant restrictions on upper limits of sugars consumption. In this review, the scientific evidence related to sugars consumption and its putative link to various chronic conditions such as obesity, diabetes, heart disease, nonalcoholic fatty liver disease, and the metabolic syndrome is examined. While it appears prudent to avoid excessive calories from sugars, the scientific basis for restrictive guidelines is far from settled.