Molecular framework integrating nitrate sensing in root and auxin-guided shoot adaptive responses.

Mineral nutrition is one of the key environmental factors determining plant development and growth. Nitrate is the major form of macronutrient nitrogen that plants take up from the soil. Fluctuating availability or deficiency of this element severely limits plant growth and negatively affects crop production in the agricultural system. To cope with the heterogeneity of nitrate distribution in soil, plants evolved a complex regulatory mechanism that allows rapid adjustment of physiological and developmental processes to the status of this nutrient. The root, as a major exploitation organ that controls the uptake of nitrate to the plant body, acts as a regulatory hub that, according to nitrate availability, coordinates the growth and development of other plant organs. Here, we identified a regulatory framework, where cytokinin response factors (CRFs) play a central role as a molecular readout of the nitrate status in roots to guide shoot adaptive developmental response. We show that nitrate-driven activation of NLP7, a master regulator of nitrate response in plants, fine tunes biosynthesis of cytokinin in roots and its translocation to shoots where it enhances expression of CRFs. CRFs, through direct transcriptional regulation of PIN auxin transporters, promote the flow of auxin and thereby stimulate the development of shoot organs.

Silicon attenuates nutritional disorder of phosphorus in seedlings of Eucalyptus grandis × Eucalyptus urophylla.

BACKGROUND: Nutritional disorders of phosphorus (P), due to deficiency or toxicity, reduce the development of Eucalyptus spp. seedlings. Phosphorus deficiency often results in stunted growth and reduced vigor, while phosphorus toxicity can lead to nutrient imbalances and decreased physiological function. These sensitivities highlight the need for precise management of P levels in cultivation practices. The use of the beneficial element silicon (Si) has shown promising results under nutritional stress; nevertheless, comprehensive studies on its effects on Eucalyptus spp. seedlings are still emerging. To further elucidate the role of Si under varying P conditions, an experiment was conducted with clonal seedlings of a hybrid Eucalyptus spp. (Eucalyptus grandis × Eucalyptus urophylla, A207) in a soilless cultivation system. Seedlings were propagated using the minicutting method in vermiculite-filled tubes, followed by treatment with a nutrient solution at three P concentrations: a deficient dose (0.1 mM), an adequate dose (1.0 mM) and an excessive dose (10 mM), with and without the addition of Si (2mM). This study assessed P and Si concentration, nutritional efficiency, oxidative metabolism, photosynthetic parameters, and dry matter production. RESULTS: Si supply increased phenolic compounds production and reduced electrolyte leakage in seedlings provided with 0.1 mM of P. On the other hand, Si favored quantum efficiency of photosystem II as well as chlorophyll a content in seedlings supplemented with 10 mM of P. In general, Si attenuates P nutritional disorder by reducing the oxidative stress, favoring the non-enzymatic antioxidant system and photosynthetic parameters in seedlings of Eucalyptus grandis × Eucalyptus urophylla. CONCLUSION: The results of this study indicate that Eucalyptus grandis × Eucalyptus urophylla seedlings are sensitive to P deficiency and toxicity and Si has shown a beneficial effect, attenuating P nutritional disorder by reducing the oxidative stress, favoring the non-enzymatic antioxidant system and photosynthetic parameters.

Intermittent normobaric hypoxia alters substrate partitioning and muscle oxygenation in individuals with obesity: implications for fat burning.

This single-blind, crossover study aimed to measure and evaluate the short-term metabolic responses to continuous and intermittent hypoxic patterns in individuals with obesity. Indirect calorimetry was used to quantify changes in resting metabolic rate (RMR), carbohydrate (CHOox, %CHO), and fat oxidation (FATox, %FAT) in nine individuals with obesity pre and post: 1) breathing normoxic air [normoxic sham control (NS-control)], 2) breathing continuous hypoxia (CH), or 3) breathing intermittent hypoxia (IH). A mean peripheral oxygen saturation ([Formula: see text]) of 80-85% was achieved over a total of 45 min of hypoxia. Throughout each intervention, pulmonary gas exchanges, oxygen consumption (V̇o2) carbon dioxide production (V̇co2), and deoxyhemoglobin concentration (Δ[HHb]) in the vastus lateralis were measured. Both RMR and CHOox measured pre- and postinterventions were unchanged following each treatment: NS-control, CH, or IH (all P > 0.05). Conversely, a significant increase in FATox was evident between pre- and post-IH (+44%, P = 0.048). Although the mean Δ[HHb] values significantly increased during both IH and CH (P < 0.05), the greatest zenith of Δ[HHb] was achieved in IH compared with CH (P = 0.002). Furthermore, there was a positive correlation between Δ[HHb] and the shift in FATox measured pre- and postintervention. It is suggested that during IH, the increased bouts of muscle hypoxia, revealed by elevated Δ[HHb], coupled with cyclic periods of excess posthypoxia oxygen consumption (EPHOC, inherent to the intermittent pattern) played a significant role in driving the increase in FATox post-IH.

Defining "low-carb" in the scientific literature: A scoping review of clinical studies.

There remains a lack of scientific consensus on what level of carbohydrate intake constitutes low-carbohydrate diets. We conducted a scoping review to understand how low-carbohydrate diets were defined in the peer-reviewed literature. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement scoping review extension. Three electronic databases were searched for clinical studies in English. We identified 508 articles (317 randomized controlled, 99 cross-over, 33 before-and-after, 12 non-randomized, and 47 other clinical trials). Most examined effects of low-carbohydrate diets in healthy adults (62.4%), 40 to 59 years old (55.5%), with obesity or overweight (66.1%). The majority reported effects on weight or body composition (29.9%), diabetes (18.7%), or cardiovascular risk factors (12.9%) as primary outcomes. Most articles (56.9%) reported percent of energy from carbohydrates, and of those, 60.3% defined low-carbohydrate diets as being ≤30% of energy from carbohydrates. Some articles (22.9%) reported grams of carbohydrates per day, and of those, most defined low-carbohydrate diets as being under ∼100 grams of carbohydrates per day. Systematic reviews and dose-response meta-regressions utilizing patient-level data on carbohydrate intake, status markers (e.g., RQ/ketones), and health outcomes would be useful in informing consensus around a standardized definition.

Early-life nutrition is associated with processing speed at age 5 in children born preterm with very low birth weight.

OBJECTIVE: Processing speed is suboptimal among preterm-born children which is of concern as it is a foundational skill supporting higher-level cognitive functions. The study objective was to evaluate associations between early-life nutrition and processing speed in childhood. METHODS: Macronutrient and human milk (mother's own, donor) intakes from 137 children born preterm with very low birth weight enrolled in a nutrition feeding trial were included. Processing speed was evaluated at age 5 using the Wechsler Preschool and Primary Scale of Intelligence-fourth edition Processing Speed Index. Associations between early-life nutrition and processing speed were explored through linear regression. RESULTS: Children had a mean (standard deviation [SD]) birth gestational age of 28.1 (2.5) weeks, weight of 1036 (260) g and 52% were male. The mean (SD) assessment age was 5.7 (0.2) years. Sex-dependent relationships were identified between first postnatal month protein, lipid and energy intakes and processing speed at 5 years. For females, lower protein (per 0.1 g/kg/d: -0.88, 95% confidence interval [CI]: -1.53, -0.23; p = 0.01) and energy (per 10 kcal/kg/d: -2.38, 95% CI: -4.70, -0.05; p = 0.03) intakes were related to higher processing speed scores. Mother's milk provision was positively associated (per 10% increase: 0.80, 95% CI: 0.22, 1.37; p = 0.01) and donor milk was negatively associated (per 10% increase: -1.15, 95% CI: -2.22, -0.08; p = 0.04) with processing speed scores; no sex differences were observed. CONCLUSIONS: First postnatal month nutrition was related to processing speed at age 5 in children born preterm with very low birth weight. Early-life nutrition that supports processing speed may be leveraged to improve later cognitive outcomes for this vulnerable population.

Relationship between dietary fiber to carbohydrate ratio and mortality risk in US adults: NHANES 2007-2018.

BACKGROUND AND AIMS: The evidence is inconsistent regarding associations between relative proportions of macronutrient intake and disease risk, potentially due to limitations in accounting for differential effects of simple sugars and dietary fiber, grouped as "carbohydrates." We examined the association between the ratio of dietary fiber to carbohydrate intake (FC-R) measure, the relative proportion of macronutrients, and mortality risk in a nationally representative sample of U.S. adults. METHODS AND RESULTS: We performed a retrospective cohort study, using data from the National Health and Nutrition Examination Survey in 2007-2018 and linked mortality data among 15,789 adults aged ≥40 years. We categorized participants into three groups by tertile cutpoints of FC-R, and by percent calories from carbohydrate (<45 %, 45-65 %, and >65 %). Cox proportional hazards regression was performed to estimate hazard ratios (HR) for all-cause mortality with 95 % confidence intervals (95 % CI), adjusting for demographic, health history, and lifestyle factors. During a median follow-up of 6.5 years, 2044 deaths were observed. Compared to the low FC-R group, higher FC-R groups showed a reduction in mortality risk after adjusting for potential confounders (high vs low: HR = 0.71, 95 % CI = 0.62-0.83). The association persisted in those consuming 45-65 % and >65 % of calories from carbohydrate, while the association was attenuated in those with <45 % of calories from carbohydrate. Percent calories from carbohydrate showed no association with mortality risk. CONCLUSION: Higher FC-R was associated with lower all-cause mortality risk in adults with moderate to high levels of percent calories from carbohydrate. Mechanisms of the association warrant further investigation.

Influence of morbidity, early nutritional intake, and total energy: protein ratio on longitudinal extrauterine growth restriction of very preterm newborns at term-equivalent age: an observational study.

To evaluate the influence of early nutritional intake on the growth pattern of very preterm infants. This was an observational study including 109 newborns (< 32 weeks gestational age). Perinatal morbidities, nutritional therapy (first four weeks of life), and weight, length, and head circumference (HC) growth at term-equivalent age were evaluated. Growth restriction was defined as a difference > 1.2 SD between the birth and term age measurements. Growth restriction at term-equivalent age: 52.3% (weight), 42.9% (length), and 22% (HC). Morbidities were positively correlated with nutrition therapy and negatively correlated with the total energy provision: protein ratio. The duration of parenteral nutrition, the time to reach full enteral feedings, and the total energy provision: protein ratio were significantly correlated. Nutrient intake influenced weight, length, and HC growth, and cumulative energy deficit was significantly associated with HC growth restriction.   Conclusion: Perinatal morbidities interfere with nutritional therapy and early nutrient intake, leading to insufficient energy and energy provision: protein ratio for growth. What is Known: • The intake of macronutrients early in life, mainly protein, is important for the optimal growth of pretem infants. • The severity of morbidities and low gestational ages impact the nutritional management of preterm infants. What is New: • The number of morbidities, reflecting the severity of the neonatal clinical course, had a detrimental effect on the nutritional therapy and nutrients intake. • The inadequate energy provision per gram of protein ratio was significantly associated with growth restriction in all growth measures at the second week of life, persisting for head circumference up to the fourth week, highlighting the importance of its measurement, as it could be a precocious sign of development risk.

Maternal macronutrient and energy intake during pregnancy: a systematic review and meta-analysis.

BACKGROUND: Nutritional status during pregnancy can have a significant impact on infant and maternal health outcomes. To maintain maternal homeostasis and support fetal growth, adequate macronutrient and energy intake during pregnancy is essential. Therefore, this study sought to systematically review and meta-analyze macronutrient and energy intakes during pregnancy. METHODS: A systematic review and meta-analysis was carried out based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The required data were collected from four databases including: Web of Sciences, ProQuest, Scopus, and PubMed, from 1 January 1980 to 30 May 2023, by using a combination of search terms (dietary pattern" OR "diet quality" OR "food habits" OR "nutrition surveys" OR "diet surveys" OR "food-frequency questionnaire" OR "diet record" OR "dietary recall") AND ( "pregnancy" OR "reproduction" OR "maternal health" OR "neonatal outcomes") among interventional and observational studies. Excel and STATA version 11 were used for data analysis. RESULTS: Among 7081 published articles, 54 studies were included in the review. Most of the 33 (61%) studies were cohort studies and a total of 135,566 pregnant women were included. The overall average of energy, carbohydrate, fat, and protein intake was 2036.10 kcal/day, 262.17 gr/day, 74.17 gr/day, and 78.21 gr/day, respectively. Also, energy intake during pregnancy was higher in American (2228.31 kcal/day, CI95%: 2135.06-2325.63) and Eastern Mediterranean regions (2226.70 kcal/day, CI95%: 2077.23-2386.92) than other regions (P < 0.001). Energy intake was higher in the third trimester than others (2115.64 kcal/day, CI95%: 1974.15-2267.27). Furthermore, based on the findings, there was a significant difference between energy intake in different World Health Organization (WHO) regions (P < 0.05). CONCLUSIONS: According to the results of meta-analysis, the average total energy was below than average total energy required during pregnancy. More efforts are needed to encourage women to adopt healthy eating habits during pregnancy to support healthy fetal and infant development.

The effects of trade liberalization on inequality in nutrition intake: empirical evidence from Indian districts.

BACKGROUND: Despite the positive impact of trade liberalization on food availability in India, severe inequality in nutrition consumption at the district level persists. Empirical evidence on the relationship between trade liberalization and nutrition consumption inequality often offers a country-level perspective and generates disputed outcomes. The study aimed to explore the effects of trade liberalization on inequality in nutrition consumption at the district level in India and to examine the heterogeneity of the impact on different nutrition consumption. METHODS: Our study employed the Gini Index to measure nutrition consumption inequality of 2 macronutrients and 5 micronutrients at the district level in India during 2009-2011, utilizing the comprehensive FAO/WHO individual food consumption data. The import tariff was adopted as a proxy for trade liberalization, as its externally imposed nature facilitates a causal interpretation. We further identified the direct causal relationship between food trade liberalization and inequality in nutrition consumption using a fixed effects model. RESULTS: The results show that more than 50% of the individuals in the survey districts did not meet the dietary standards for both macronutrients and micronutrients. Food trade liberalization hindered the improvement of inequality in nutrition consumption. As import tariffs were reduced by 1%, the inequality in intake of calories, zinc, vitamin B1, and vitamin B2 increased significantly by 0.45, 0.56, 0.48, and 0.66, respectively, which might be related to food market performance. The results also highlight the positive role of the gender gap, female-headed households, and caste culture on inequality in nutrition consumption in India. CONCLUSIONS: To ease the shock of liberalization and minimize its inequality effects, complementary measures should be adopted, such as improving food logistic conditions in poor areas, and nutrition relief schemes.

Postprandial metabolism and gut permeability in calves fed milk replacer with different macronutrient profiles or a whole milk powder.

Significant differences exist in the composition of current milk replacers (MR) and bovine whole milk. This study investigated how the macronutrient profile of 3 different MR formulations containing varying amounts of fat, lactose, and protein, and a whole milk powder (WP), affect postprandial metabolism and gut permeability in male Holstein calves. Sixty-four calves (45.4 ± 4.19 kg [mean ± SD] and 1.8 ± 0.62 d of age) were blocked in order of arrival to the facility and within each block, calves were randomly assigned to 1 of 4 treatments. Treatments included a high-fat MR (HF: 25.0% dry matter [DM] fat, 22.5% protein, 38.6% lactose; n = 14), a high-lactose MR (HL: 44.6% lactose, 22.5% protein, 18.0% fat; n = 17), a high-protein MR (HP: 26.0% protein, 18.0% fat, 41.5% lactose; n = 17), and WP (26.0% fat, 24.5% protein, 38.0% lactose; n = 16). Calves were fed 3.0 L (135 g/L) 3 times daily at 0600, 1200, and 1800 h with a teat bucket. Milk intake was recorded daily for the first 28 d after arrival, and blood sampling and body weight measurements were performed at arrival and on d 7, 14, 21, and 27. Gut permeability was estimated from fractional urinary excretion of indigestible markers (Cr-EDTA, lactulose, and d-mannitol) administered as a single dose on d 21 instead of the morning milk meal. Digestibility was determined simultaneously from a total collection of feces over 24 h. Postprandial dynamics were measured on d 28 by sequential blood sampling over 7.5 h. Dry matter intake of MR over 28 d was slightly greater in calves fed HL and HP than in WP. Recovery of Cr-EDTA and d-mannitol over a 24-h urine collection was greater in calves fed WP and HP than HL calves. Apparent total-tract digestibility of crude ash, protein, and fat did not differ among treatments; however, DM digestibility was lower in calves fed WP than in other treatment groups. In addition, abomasal emptying, as indicated by the area under the curve (AUC) for acetaminophen, was slower in calves fed WP than in calves fed HF and HL. The AUC for postprandial plasma glucose was lower in calves fed HL than WP and HF and lower in calves fed HP than WP. The AUC for postprandial serum insulin was greater in calves fed HP than WP and HF, whereas calves fed HL did not differ from the other treatments. Postprandial triglycerides were greater in calves fed WP, and postprandial adiponectin was higher in calves fed HL than other treatments. The high content of lactose and protein in MR had a major effect on postprandial metabolism. This raises the possibility of optimizing MR formulations to maintain metabolic homeostasis and influence development.

Effect of digestible protein on intermediate metabolism, hepatic enzyme activities, energy reserves, and growth performance of pacu (Piaractus mesopotamicus) in the finishing growth phase.

This study investigated the effect of different levels of digestible protein (DP) on blood metabolites, hepatic enzyme activity of glycolysis and amino acid metabolism, energy reserves, and the production characteristics of pacu (Piaractus mesopotamicus) during the finishing growth phase. Six semi purified and isoenergetic diets, containing 16.3, 20.1, 23.8, 27.2, 31.5, and 34.8% of balanced DP, provided with essential amino acid balance, were hand-fed to pacu (1100.0 ± 10.3 g, initial weight) three times daily for 7 weeks. The experiment consisted of six treatments, with three randomly arranged replicates (tanks) per treatment. The data obtained from this experiment were analyzed by one-way analysis of variance (ANOVA), and significant differences (p < 0.05) between treatments were determined using Tukey's test. Blood metabolites, except serum ammonia and the hepatic enzymes activities of glycolysis and amino acid metabolism, except hexokinase activity were affected (p < 0.05) by balanced DP. The energy reserve indices, except hepatic total lipid content, were also found associated (p < 0.05) with balanced DP. The test diets significantly (p < 0.05) affected growth performance parameters. Higher dietary proteins led to a greater energy uptake by fish from the protein in feed. Overall, fish fed the intermediate level (23.8%) of balanced DP with digestible energy of 17.95 MJ kg-1 showed better production traits and physio-biochemical health markers. This information could help nutritionists and farmers to develop nutritionally balanced and economically and environmentally sustainable aquafeed for promoting healthy and sustainable production of pacu in intensive culture systems.

[Relationship between the percentage of energy intake from macronutrients and obesity among adult residents in 15 provinces of China in 1991-2018].

OBJECTIVE: To explore the relationship between the percentage of energy intake from macronutrients and obesity in Chinese adult residents, and analyze the cut-off values of macronutrients for predicting obesity. METHODS: Data was collected in China Health and Nutrition Survey(CHNS)in 1991-2018. Adults who participated in at least two waves of the surveys and were not obese at baseline were selected as the study subjects. Obesity was defined as body mass index(BMI)≥28.0 kg/m~2. Generalized estimating equation was used to analyze the relationship between the percentage of energy intake from macronutrients and BMI and obesity, and receiver operating characteristic curve(ROC) was used to analyze the cut-off values of percentage of energy intake from macronutrients to predict obesity. RESULTS: The percentage of energy intake from protein and fat of adult residents in 15 provinces(autonomous regions and municipalities) in China showed an increasing trend(P<0.01), and the percentage of energy intake from carbohydrate showed a decreasing trend(P<0.01) between 1991 and 2018. After adjusting for covariates, the group of percentage of energy intake from fat in 20%～30%(ß=0.05, 95%CI 0.01-0.08)and ≥30%(ß=0.15, 95%CI 0.11-0.18)were positively correlated with BMI compared with the group of percentage of energy intake from fat <20%, and the risk of obesity in 20%-30% and ≥ 30% was increased by 17%(OR=1.17, 95%CI 1.04-1.31)and 6%(OR=1.06, 95%CI 1.24-1.56), respectively. Compared with the group of the percentage of energy intake from carbohydrate < 50%, the group of 50% to 65%(ß=-0.08, 95% CI-0.11--0.05) and ≥ 65%(ß=-0.17, 95%CI-0.20--0.13) was negatively correlated with BMI, and the percentage of energy intake from carbohydrate ≥ 65% reduced the risk of obesity(OR=0.71, 95%CI 0.63-0.80). CONCLUSION: Carbohydrate intake was inversely correlated with the risk of obesity, and fat intake was positively correlated with the risk of obesity. Moderate intake of carbohydrates and reduced fat intake can prevent obesity.

Post-nursing early life macronutrient balance promotes persistent and malleable biometric and metabolic traits in mice.

It is known that dietary factors within the gestational and nursing period affect early life and stably affect later life traits in animals. However, there is very little understanding of whether dietary factors within the early life period from post-nursing to adulthood affect traits in adulthood. To address this, we conducted studies on male C57Bl/6J mice fed from 3 weeks (immediately post-nursing) until 12 weeks (full maturity) using nine different diets varying in all three major macronutrients to parse out the effects of individual macronutrients. Early life macronutrient balance affected body composition and glucose homeostasis in early adulthood, with dietary protein and fat showing major effects. Despite this, mice showed rapid reversal of the effects on body composition and glucose homeostasis of early life diet feeding, upon standard diet feeding in adulthood. However, some traits were persistent, with early life low dietary protein levels stably affecting lean and muscle mass, and early life dietary fat levels stably affecting serum and liver triglyceride levels. In summary, macronutrient balance in the post-nursing early life period does not stably affect adiposity or glucose homeostasis but does impact muscle mass and lipid homeostasis in adulthood, with prominent effects of both protein and fat levels. KEY POINTS: Early life dietary low protein and high fat levels lowered and heightened body mass, respectively. These effects did not substantially persist into adulthood with rapid catch-up growth on a normal diet. Early life protein (negative) and fat (positive) levels affected fat mass. Early life low protein levels negatively affected lean mass. Low protein effects on lower lean and muscle mass persisted into adulthood. Early life macronutrient balance effects did not affect later life glucose homeostasis but early life high fat level affected later life dyslipidaemia. Effects of dietary carbohydrate levels in early and later life were minor.

Meal sugar-protein balance determines postprandial FGF21 response in humans.

Biological mechanisms to promote dietary balance remain unclear. Fibroblast growth factor 21 (FGF21) has been suggested to contribute to such potential regulation considering that FGF21 1) is genetically associated with carbohydrate/sugar and protein intake in opposite directions, 2) is secreted after sugar ingestion and protein restriction, and 3) pharmacologically reduces sugar and increases protein intake in rodents. To gain insight of the nature of this potential regulation, we aimed to study macronutrient interactions in the secretory regulation of FGF21 in healthy humans. We conducted a randomized, double-blinded, crossover meal study (NCT05061485), wherein healthy volunteers consumed a sucrose drink, a sucrose + protein drink, and a sucrose + fat drink (matched sucrose content), and compared postprandial FGF21 responses between the three macronutrient combinations. Protein suppressed the sucrose-induced FGF21 secretion [incremental area under the curve (iAUC) for sucrose 484 ± 127 vs. sucrose + protein -35 ± 49 pg/mL × h, P < 0.001]. The same could not be demonstrated for fat (iAUC 319 ± 102 pg/mL × h, P = 203 for sucrose + fat vs. sucrose). We found no indications that regulators of glycemic homeostasis could explain this effect. This indicates that FGF21 responds to disproportionate intake of sucrose relative to protein acutely within a meal, and that protein outweighs sucrose in FGF21 regulation. Together with previous findings, our results suggests that FGF21 might act to promote macronutrient balance and sufficient protein intake.NEW & NOTEWORTHY Here we test the interactions between sugar, protein, and fat in human FGF21 regulation and demonstrate that protein, but not fat, suppresses sugar-induced FGF21 secretion. This indicates that protein outweighs the effects of sugar in the secretory regulation of FGF21, and could suggest that the nutrient-specific appetite-regulatory actions of FGF21 might prioritize ensuring sufficient protein intake over limiting sugar intake.

Modifying Dietary Protein Impacts mTOR Signaling and Brain Deposition of Amyloid ß in a Knock-In Mouse Model of Alzheimer Disease.

BACKGROUND: Alzheimer disease (AD) is a neurodegenerative condition defined by the build-up of amyloid plaques in the brain and intraneuronal tangles of the protein tau. Autophagy is a cellular cleaning process involved in the degradation of proteins, including proteins directly responsible for amyloid plaques, but its activity is compromised in AD. The mechanistic target of rapamycin complex (mTORC) 1 inhibits autophagy when activated by amino acids. OBJECTIVES: We hypothesized that reducing amino acid intake by decreasing dietary protein could promote autophagy, which in turn could prevent amyloid plaque deposition in AD mice. METHODS: Homozygote (2-mo-old) and heterozygote (4-mo-old) amyloid precursor protein NL-G-F mice, a model of brain amyloid deposition, were used in this study to test this hypothesis. Male and female mice were fed with isocaloric low-protein, control, or high-protein diets for 4 mo and killed for analysis. Locomotor performance was measured using the inverted screen test, and body composition was measured using EchoMRI. Samples were analyzed using western blotting, enzyme-linked immunosorbent assay, mass spectrometry, and immunohistochemical staining. RESULTS: mTORC1 activity in the cerebral cortex was inversely covaried with protein consumption in both homozygote and heterozygote mice. Low-protein diet improved metabolic parameters and restored locomotor performance only in male homozygous mice. Dietary protein adjustment did not affect amyloid deposition in homozygous mice. However, in the heterozygous amyloid precursor protein NL-G-F mice, amyloid plaque was lower in male mice consuming the low protein compared with that in mice fed with the control diet. CONCLUSIONS: This study showed that reducing protein intake reduces mTORC1 activity and may prevent amyloid accumulation, at least in male mice. Moreover, dietary protein is a tool that can be used to change mTORC1 activity and amyloid deposition in the mouse brain, and the murine brain's response to dietary protein is sex specific.

Mapping the nutritional landscape in the yellow mealworm: testing the nutrient-mediated life-history trade-offs.

Animals must acquire an ideal amount and balance of macronutrients to optimize their performance, health and fitness. The nutritional landscape provides an integrative framework for analysing how animal phenotypes are associated with multiple nutritional components. Here, we applied this powerful approach to examine how the intake of protein and carbohydrate affects nutrient acquisition and performance in the yellow mealworm (Tenebrio molitor) reared on one of 42 synthetic foods varying in protein and carbohydrate content. Tenebrio molitor larvae increased their food consumption rate in response to nutrient dilution, but this increase was not sufficient to fully compensate for the dilution. Diluting the food nutrient content with cellulose reduced the efficiency of post-ingestive nutrient utilization, further restricting macronutrient acquisition. Tenebrio molitor larvae utilized macronutrients most efficiently at a protein to carbohydrate (P:C) ratio of 1.77:1, but became less efficient at imbalanced P:C ratios. Survivorship was high at high protein intake and fell with decreasing protein intake. Pupal mass and growth rate exhibited a bell-shaped landscape, with the nutritional optima being located around protein-biased P:C ratios of 1.99:1 to 2.03:1 and 1.66:1 to 2.86:1, respectively. The nutritional optimum for development time was also identified at high P:C ratios (1.66:1  to 5.86:1). Unlike these performance traits, lipid content was maximized at carbohydrate-biased P:C ratios of 1:3.88 to 1:3.06. When given a food choice, T. molitor larvae self-composed a slightly carbohydrate-biased P:C ratio of 1:1.24, which lies between the P:C ratios that maximize performance and lipid content. Our findings indicate the occurrence of a nutrient-mediated trade-off between performance and energy storage in this insect.

Energy intakes, macronutrient intakes and the percentages of energy from macronutrients with adolescent BMI: results from a 5-year cohort study in Ho Chi Minh City, Vietnam.

BACKGROUND: Adolescence is a period of life when dietary patterns and nutrient intakes may greatly influence adult fatness. This study assesses the tracking of energy and nutrient intakes of Ho Chi Minh City adolescents over 5 years. It explores the possible relationships between energy and the percentage of energy from macronutrients with BMI. METHODS: Height, weight, time spent on physical activity, screen time and dietary intakes were collected annually between 2004 and 2009 among 752 junior high school students with a mean age of 11·87 years at baseline. The tracking was investigated using correlation coefficients and weighted kappa statistics (k) for repeated measurements. Mixed effect models were used to investigate the association between energy intakes and percentage energy from macronutrients with BMI. RESULTS: There were increases in the mean BMI annually, but greater in boys than in girls. Correlation coefficients (0·2 < r < 0·4) between participants' intakes at baseline and 5-year follow-up suggest moderate tracking. Extended kappa values were lowest for energy from carbohydrate (CHO) in both girls and boys (k = 0·18 & 0·24, respectively), and highest for protein in girls (k = 0·47) and fat in boys (k = 0·48). The multilevel models showed the following variables significantly correlated with BMI: CHO, fat, percentage of energy from CHO, fat, time spent for moderate to vigorous physical activity, screen time, age and sex. CONCLUSIONS: The poor to fair tracking observed in this cohort suggests that individual dietary patterns exhibited in the first year are unlikely to predict energy and nutrient intakes in the fifth year.

Associations between breast milk intake volume, macronutrient intake and infant growth in a longitudinal birth cohort: the Cambridge Baby Growth and Breastfeeding Study (CBGS-BF).

Growth patterns of breastfed infants show substantial inter-individual differences, partly influenced by breast milk (BM) nutritional composition. However, BM nutritional composition does not accurately indicate BM nutrient intakes. This study aimed to examine the associations between both BM intake volumes and macronutrient intakes with infant growth. Mother-infant dyads (n 94) were recruited into the Cambridge Baby Growth and Breastfeeding Study (CBGS-BF) from a single maternity hospital at birth; all infants received exclusive breast-feeding (EBF) for at least 6 weeks. Infant weight, length and skinfolds thicknesses (adiposity) were repeatedly measured from birth to 12 months. Post-feed BM samples were collected at 6 weeks to measure TAG (fat), lactose (carbohydrate) (both by 1H-NMR) and protein concentrations (Dumas method). BM intake volume was estimated from seventy infants between 4 and 6 weeks using dose-to-the-mother deuterium oxide (2H2O) turnover. In the full cohort and among sixty infants who received EBF for 3+ months, higher BM intake at 6 weeks was associated with initial faster growth between 0 and 6 weeks (ß + se 3·58 + 0·47 for weight and 4·53 + 0·6 for adiposity gains, both P < 0·0001) but subsequent slower growth between 3 and 12 months (ß + se - 2·27 + 0·7 for weight and -2·65 + 0·69 for adiposity gains, both P < 0·005). BM carbohydrate and protein intakes at 4-6 weeks were positively associated with early (0-6 weeks) but tended to be negatively related with later (3-12 months) adiposity gains, while BM fat intake showed no association, suggesting that carbohydrate and protein intakes may have more functional relevance to later infant growth and adiposity.

Self-selected meal composition alters the relationship between same-day caloric intake and appetite scores in humans during a long-term ad-libitum feeding study.

PURPOSE: To determine the effect of an off-protocol meal during a long-term ad libitum feeding study on changes in total caloric consumption and ratings of hunger and satiety. METHODS: During the ad libitum portion of a 16 weeks research high-protein feeding study, 19 participants were allowed to eat up to one self-selected meal (SSM) a week instead of an intervention diet meal. The SSM was assessed for total caloric and macronutrient composition and compared to the intervention diet for 3 days before and after the SSM day. Visual analog scores rating daily hunger and fullness were collected and compared as well. RESULTS: On the SSM day, the mean ± SD daily caloric intake increased by 262 ± 332 kcal compared to the previous study days (P < 0.001), with no changes in subjective appetite scores. The following day there was a slight but significant reduction in intake (- 58 ± 85 kcal, P = 0.008) compared to the average pre-SSM day with no change in appetite scores. On the SSM day, percent protein intake was inversely associated mean daily caloric intake (r2 = 0.22, P = 0.03). CONCLUSIONS: During a long-term, ad-libitum high-protein feeding study, one SSM lower in protein increased daily total caloric consumption with no impact on appetite ratings and incomplete caloric consumption during subsequent days. These data suggest that during ad-libitum feeding, a single meal change in protein content impacts the relationships between daily level of hunger, satiety and calorie intake. GOV ID: NCT05002491 (retrospectively registered 07/20/2021).

Maternal melatonin levels and temporal dietary intake: results from MY-CARE cohort study.

Chrononutrition emerges as a novel approach to promote circadian alignment and metabolic health by means of time-of-the-day dietary intake. However, the relationship between maternal circadian rhythm and temporal dietary intake during pregnancy remains understudied. This study aimed to determine the change in melatonin levels in pregnant women across gestation and its association with temporal energy and macronutrient intake. This was a prospective cohort involving 70 healthy primigravidas. During the second and third trimesters, pregnant women provided salivary samples collected at 9:00, 15:00, 21:00, and 3:00 h over a 24 h day for melatonin assay. Data on chrononutrition characteristics were collected using a 3-day food record. Parameters derived from melatonin measurements including mean, amplitude, maximal level, area under the curve with respect to increase (AUCI), and area under the curve with respect to ground (AUCG) were computed. A rhythmic melatonin secretion over the day that remained stable across trimesters was observed among the pregnant women. There was no significant elevation in salivary melatonin levels as pregnancy advanced. In the second trimester, higher energy intake during 12:00-15:59 h and 19:00-06:59 h predicted a steeper melatonin AUCI (ß=-0.32, p = 0.034) and higher AUCG (ß = 0.26, p = 0.042), respectively. Macronutrient intake within 12:00-15:59 h was negatively associated with mean melatonin (Fat: ß=-0.28, p = 0.041) and AUCG (Carbohydrate: ß=-0.37, p = 0.003; Protein: ß=-0.27, p = 0.036; Fat: ß=-0.32, p = 0.014). As pregnant women progressed from the second to the third trimester, a flatter AUCI was associated with a reduced carbohydrate intake during 12:00-15:59 h (ß=-0.40, p = 0.026). No significant association was detected during the third trimester. Our findings show that higher energy and macronutrient intakes particularly during 12:00-15:59 h and 19:00-06:59 h are associated with the disparities in maternal melatonin levels. Findings suggest the potential of time-based dietary approaches to entrain circadian rhythm in pregnant women.