Tag: nutrition

Talking to Your Child About Weight: A Family Approach

On By Dr. Scott RennieIn Weight Loss & Metabolic HealthLeave a comment

Pediatric obesity affects nearly one in five children in the United States (Stierman B, Afful J, Carroll MD, et al. National Health Statistics Reports, No. 158, 2021). In primary care, we’re often the first to see the signs. We see families regularly. That gives us a real chance to guide prevention and help establish healthy habits early.

The American Academy of Pediatrics recommends eleven visits in the first two years of life. Those visits do more than cover vaccines and ear checks: they’re a chance to track growth, notice concerning patterns early, and build trust with parents. Short counseling moments, repeated over time, often make more impact than a single long lecture. Small doses, consistently given.

The Chronic Care Model gives us a structure to work from. It starts with decision support, like using BMI and growth charts to flag risk. It builds in self-management tools such as plate planners that make meal discussions concrete, emphasizes delivery system design, and connects practices to community resources so families don’t feel like they’re managing this on their own (Dietz WH, Lee J, Wechsler H, Malepati S, Sherry B. Health Affairs. 2007, 26(2):430-440).

During pregnancy, maternal smoking and psychological stress both raise a child’s later obesity risk (Rayfield S, Plugge E. J Epidemiol Community Health. 2017, 71:162-173) (Dancause KN, Laplante DP, Oremus C, Fraser S, Brunet A, King S. Pediatr Res. 2012, 71:126-131). From birth through the toddler years, setting expectations around normal growth and picky eating helps prevent overfeeding. In preschool and elementary school, reinforcing habits around meals and activity can keep BMI from drifting up. Once kids reach adolescence, weight management often needs more direct intervention (Cardel MI, Atkinson MA, Taveras EM, Holm JC, Kelly AS. JAMA Pediatr. 2020, 174:609-617).

Parental obesity, maternal smoking during pregnancy, a chaotic home feeding environment: all of it raises the odds of rapid early weight gain (Stettler N, Zemel BS, Kumanyika S, Stallings VA. Pediatrics. 2002, 109:194-199). These are the kids who benefit most from structured follow-up.

Meta-analyses show up to a 22 percent reduction in obesity risk from breastfeeding, though the effect drops to about 7 to 10 percent once you adjust for maternal obesity and socioeconomic status (Owen CG, Martin RM, Whincup PH, Smith GD, Cook DG. Pediatrics. 2005, 115:1367-1377) (Harder T, Bergmann R, Kallischnigg G, Plagemann A. Am J Epidemiol. 2005, 162:397-403). Breastfed infants are better at regulating their own intake, and breastmilk itself carries bioactive compounds that affect metabolism (Arenz S, Rückerl R, Koletzko B, von Kries R. Int J Obes (Lond). 2004, 28:1247-1256).

I often tell parents to expect a “three-day eating cycle” in toddlers. One day they eat well, the next they pick at food, the third day they do something in between. Framing it this way reassures parents and heads off unnecessary pressure at mealtime. Another helpful concept is covert restriction, simply not bringing high-calorie snacks into the house in the first place. That avoids turning junk food into a “forbidden fruit” while still shaping healthier choices (Ogden J, Reynolds R, Smith A. Appetite. 2006, 47:100-106).

Motivational interviewing works by asking how they view their child’s weight, showing growth charts, and framing recommendations without blame: all of it makes these conversations more effective (Barlow SE. Pediatrics. 2007, 120 Suppl 4:S164-192). Simple, achievable goals work better than long lists. I often start with two diet-related changes, like reducing sugary drinks and adding vegetables, and one activity change, such as more outdoor play.

Checking in every three months, celebrating small wins, reinforcing progress: that’s what keeps families engaged. Counseling doesn’t need to be perfect. It needs to be consistent.

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Sources:

How Obesity in Pregnancy Affects the Baby and Placenta

On By Dr. Scott RennieIn Menopause & Women's Health, Weight Loss & Metabolic HealthLeave a comment

As healthcare providers, we’ve long recognized the importance of maternal health in shaping pregnancy outcomes. What’s become clearer in recent years is the role of epigenetics, changes in gene expression that don’t alter DNA itself but influence how genes are turned on or off.

When we look at pregnancies complicated by obesity, DNA methylation patterns in the placenta are altered, with increased methylation suppressing genes that matter for nutrient transport and fetal growth. DNA hydroxymethylation, usually tied to active gene expression, tends to drop at the same time. One study found a 21 percent increase in methylated regions and a 31 percent decrease in hydroxymethylated regions in placentas from obese pregnancies compared with lean ones (Mitsuya K, Parker AN, Liu L, Ruan J, Vissers MCM, Myatt L. PLOS ONE. 2017, 12(10):e0186115).

These changes show up directly in the structure and function of the placenta. Inflammatory changes are common, disrupting hormonal signals and communication between maternal and fetal systems, while lipid buildup in placental cells interferes with normal function and impaired blood vessel development slows villous maturation, reducing the placenta’s ability to exchange oxygen and nutrients efficiently (Saben J, Lindsey F, Zhong Y, et al. Placenta. 2014, 35:171-177).

Mitochondrial function also suffers. Placental cells from obese pregnancies generate less ATP through oxidative phosphorylation. Less energy available means nutrient transport and other vital processes get compromised, which can directly affect fetal growth and development (Mele J, Muralimanoharan S, Maloyan A, Myatt L. Am J Physiol Endocrinol Metab. 2014, 307:E419-E425).

The clinical consequences are real. Growth restriction at one extreme, excessive growth at the other. Both ends of that spectrum carry a higher risk of metabolic problems later in life, including insulin resistance and obesity (Ornoy A. Reprod Toxicol. 2011, 32:205-212).

In practice, weight and metabolic health before and during pregnancy matter more than we once realized. Supporting women to reach a healthier weight before conception can reduce risks. During pregnancy, balanced diets built around whole foods, healthy fats, and complex carbohydrates can help improve metabolic stability. For women with metabolic dysfunction, medications such as metformin may play a role in improving insulin sensitivity.

Regular follow-up lets us track maternal health and fetal growth, and adjust care as needed. The goal reaches past the pregnancy itself. Reducing the child’s long-term risk of obesity and metabolic disease matters just as much.

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Sources:

  • 1. Mitsuya K, Parker AN, Liu L, Ruan J, Vissers MCM, Myatt L. Alterations in the placental methylome with maternal obesity and evidence for metabolic regulation. PLOS ONE. 2017;12(10):e0186115. https://pubmed.ncbi.nlm.nih.gov/29045485/
  • 2. Saben J, Lindsey F, Zhong Y, et al. Maternal obesity is associated with a lipotoxic placental environment. Placenta. 2014;35(3):171-177. https://pubmed.ncbi.nlm.nih.gov/24484739/
  • 3. Mele J, Muralimanoharan S, Maloyan A, Myatt L. Impaired mitochondrial function in human placenta with increased maternal adiposity. Am J Physiol Endocrinol Metab. 2014;307(5):E419-E425. https://pubmed.ncbi.nlm.nih.gov/25028397/
  • 4. Ornoy A. Prenatal origin of obesity and their complications: gestational diabetes, maternal overweight and the paradoxical effects of fetal growth restriction and macrosomia. Reprod Toxicol. 2011;32(2):205-212. https://pubmed.ncbi.nlm.nih.gov/21620955/

Why Your Body Fights to Regain the Weight You Lost

On By Dr. Scott RennieIn Weight Loss & Metabolic HealthLeave a comment

As physicians, we often see patients who manage to lose weight but can’t seem to keep it off. One of the biggest physiological reasons is adaptive thermogenesis. Understanding what it is, and how the brain adapts too, helps explain why long-term maintenance is so hard.

Adaptive thermogenesis is the body’s way of conserving energy after weight loss. Drop a significant amount of weight, and the body needs fewer calories to function. That makes it harder to hold on to the new weight. The research goes back decades and shows the effect clearly: people who lose ten percent or more of their body weight need roughly 300 to 400 fewer calories a day to maintain that weight than someone at the same size who never lost it (Leibel et al., NEJM, 1995; Rosenbaum et al., Am J Physiol, 2003).

It’s easiest to picture with two patients. Same height, same weight, same activity. One has always been at that weight. The other lost ten percent to get there. The second patient has to eat several hundred calories less, or burn that much more through activity, just to stay even. That’s the metabolic disadvantage weight-reduced patients live with.

What makes this harder is that adaptive thermogenesis doesn’t fade away. Studies show the effect can last for years, even after weight stays stable (Sumithran et al., NEJM, 2011; Rosenbaum et al., JCI, 2008; Martins et al., AJCN, 2020). This isn’t a short-lived adjustment. Patients have to adjust to the reality that the body keeps pushing back against weight maintenance, sometimes for years after the loss.

The brain changes too. Imaging studies show heightened activity in reward and decision-making regions like the globus pallidus, insula, and ventral striatum after weight loss. Food looks more appealing. Cravings get stronger, and resisting them gets harder. Meanwhile regions tied to satiety and control, the hypothalamus and cingulate gyrus among them, go quiet. Patients feel less full, notice their intake less, and have less control over eating. It’s a setup for regain.

Despite these challenges, there are lessons from people who succeed. The National Weight Control Registry has followed thousands of long-term maintainers. On average they eat about 100 to 150 fewer calories daily than peers at the same weight who never lost it. They move more, roughly 45 extra minutes of activity a day. They watch less television, and they show consistent awareness and restraint around eating. Nothing flashy. It just works against the biology.

Exercise, aerobic and resistance both, raises energy expenditure and helps preserve muscle mass, which supports metabolism. Mindful eating and careful tracking help patients avoid unintentional increases in intake. Structured programs and social support provide accountability, which matters when the body is working against the patient. Regular follow-up visits help sustain those behaviors.

Adaptive thermogenesis and brain adaptations stack the deck against weight maintenance. Understanding the physiology makes it easier to set realistic expectations, though, and to design strategies that work with a patient’s biology instead of against it.

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

References:

  • 1. Leibel RL, Rosenbaum M, Hirsch J. Changes in Energy Expenditure Resulting from Altered Body Weight. N Engl J Med. 1995;332:621-628. https://pubmed.ncbi.nlm.nih.gov/7632212/
  • 2. Sumithran P, Prendergast LA, Delbridge E, et al. Long-Term Persistence of Hormonal Adaptations to Weight Loss. N Engl J Med. 2011;365:1597-1604. https://pubmed.ncbi.nlm.nih.gov/22029981/
  • 3. Rosenbaum M, et al. Effects of experimental weight perturbation on skeletal muscle work efficiency in human subjects. Am J Physiol Regul Integr Comp Physiol. 2003;285:R183-R192. https://pubmed.ncbi.nlm.nih.gov/12609816/
  • 4. Rosenbaum M, et al. Leptin reverses weight loss-induced changes in regional neural activity responses to visual food stimuli. J Clin Invest. 2008;118:2583-2591. https://pubmed.ncbi.nlm.nih.gov/18568078/
  • 5. Martins C, Roekenes J, Salamati S, Gower BA, Hunter GR. Metabolic adaptation is an illusion, only present when participants are in negative energy balance. Am J Clin Nutr. 2020;112:1212-1218. https://pubmed.ncbi.nlm.nih.gov/32844188/

Does Meal Timing Affect Your Metabolism and Health?

On By Dr. Scott RennieIn Weight Loss & Metabolic HealthLeave a comment

When you eat can matter as much as what you eat. Not a fad, a measurable physiological pattern, and one most people never think to adjust. Timing affects weight management, metabolic health, and even the risk of chronic disease, and the field studying the connection between circadian rhythms and eating patterns has a name: chrononutrition.

Typical eating habits in the U.S. don’t line up well with what the research suggests is healthiest. Most people eat less than a quarter of their daily calories before noon, and more than a third after 6 p.m. The average eating window stretches nearly fifteen hours a day (Gill and Panda, 2015). That long, backloaded pattern is linked to higher body fat, worse glucose tolerance, and poorer metabolic outcomes.

Evidence favors eating earlier. In one trial, people who made breakfast their largest meal had better glucose and insulin control, felt more satisfied during the day, and lost more weight than those who made dinner the main meal (Jakubowicz et al., 2013). That tracks with circadian biology: the body handles nutrients more efficiently in the morning than late at night.

Breakfast does more than supply calories. Regular breakfast eaters tend to take in more vitamins and minerals overall (St-Onge et al., 2017), and they show lower rates of obesity and more stable weight over time. Skipping breakfast, by contrast, tracks with higher BMI, larger blood sugar swings, and greater cardiovascular risk.

Time-restricted eating fits the same pattern. Narrow the eating window to eight or twelve hours and total calorie intake often falls on its own, insulin sensitivity improves, and fat oxidation increases (Gill and Panda, 2015). Early time-restricted eating, where meals cluster in the morning and early afternoon, improves appetite control and fat metabolism specifically (Ravussin et al., 2019).

Intermittent fasting runs on the same logic. The most common version is 16:8: fast sixteen hours, eat during an eight-hour window. Alternate-day fasting has also been studied, and it produces weight loss similar to plain calorie restriction, though dropout rates run higher (Trepanowski et al., 2017).

What the science of chrononutrition shows is that timing matters. Shifting more calories to the first part of the day improves metabolism and weight control, breakfast and early meals set the body up for better glucose regulation and satiety, and time-restricted eating and intermittent fasting add tools on top of that, especially when they lean toward earlier eating windows rather than later ones. For patients, these strategies are often more about changing the clock than drastically changing the plate.

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

References:

  • Gill S, Panda S. A Smartphone App Reveals Erratic Diurnal Eating Patterns in Humans that Can Be Modulated for Health Benefits. Cell Metabolism. 2015;22(5):789-798. PMID 26411343. https://pubmed.ncbi.nlm.nih.gov/26411343/
  • Jakubowicz D, et al. High Caloric Intake at Breakfast vs. Dinner Differentially Influences Weight Loss of Overweight and Obese Women. Obesity (Silver Spring). 2013;21(12):2504-2512. PMID 23512957. https://pubmed.ncbi.nlm.nih.gov/23512957/
  • St-Onge MP, et al. Meal Timing and Frequency: Implications for Cardiovascular Disease Prevention. Circulation. 2017;135:e96-e121. PMID 28137935. https://pubmed.ncbi.nlm.nih.gov/28137935/
  • Ravussin E, et al. Early Time-Restricted Feeding Reduces Appetite and Increases Fat Oxidation But Does Not Affect Energy Expenditure in Humans. Obesity (Silver Spring). 2019;27(8):1244-1254. PMID 31339000. https://pubmed.ncbi.nlm.nih.gov/31339000/
  • Trepanowski JF, et al. Effect of Alternate-Day Fasting on Weight Loss, Weight Maintenance, and Cardioprotection Among Metabolically Healthy Obese Adults. JAMA Intern Med. 2017;177(7):930-938. PMID 28459931. https://pubmed.ncbi.nlm.nih.gov/28459931/

Does Food Order Affect Blood Sugar? What to Eat First

On By Dr. Scott RennieIn Weight Loss & Metabolic HealthLeave a comment

One of the more practical strategies to come out of recent nutrition research is food order, also called nutrient sequencing. The order in which you eat macronutrients changes how your body responds to the meal, and starting with protein, fat, or fiber before carbohydrate can blunt the post-meal glucose spike and soften the insulin response that follows it.

In a small, tightly controlled study, Shukla and colleagues found that eating vegetables and protein before carbohydrate produced a 73 percent reduction in post-meal glucose and nearly a 50 percent reduction in insulin, compared with eating carbohydrate first (Shukla et al., 2015). Touhamy and colleagues reported something similar in patients with type 2 diabetes: when carbohydrates came last, glucose peaks were 44 percent lower and glycemic variability improved (Touhamy et al., 2025).

People with obesity often report better satiety eating this way. Those with prediabetes see improved tolerance and reductions in HbA1c. Children with type 1 diabetes show smaller post-meal glucose rises when protein and fat come before carbs (Faber et al., 2018). Women with gestational diabetes also see better glycemic control with a carbohydrate-last pattern during pregnancy (Murugesan et al., 2024).

Protein and fat slow gastric emptying. That delays carbohydrate absorption and keeps the glucose peak lower. Incretin hormones like GLP-1 and GIP get stimulated too, which improves insulin sensitivity and overall glucose regulation.

It usually comes down to small shifts: a salad or a non-starchy vegetable first, a few bites of protein, a small portion of healthy fat, and only then rice or bread. Even in food cultures where carbohydrate traditionally opens the meal, reordering it is usually possible. I’ve seen patients make it work by adding a quick vegetable starter at home or choosing a protein appetizer when dining out. They often say it feels more doable than committing to a strict low-carb plan.

No food groups to cut. No restrictive plan to follow. Just change the order in which you eat, and the metabolic payoff can be substantial.

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Sources:

  • Shukla AP, Iliescu RG, Thomas CE, Aronne LJ. Food Order Has a Significant Impact on Postprandial Glucose and Insulin Levels. Diabetes Care. 2015;38(7):e98-e99. PMID 26106234. https://pubmed.ncbi.nlm.nih.gov/26106234/
  • Touhamy S, et al. Carbohydrates-Last Food Order Improves Time in Range and Reduces Glycemic Variability. Diabetes Care. 2025;48(2):e15-e16. PMID 39688621. https://pubmed.ncbi.nlm.nih.gov/39688621/
  • Faber EM, van Kampen PM, Clement-de Boers A, Houdijk ECAM, van der Kaay DCM. The Influence of Food Order on Postprandial Glucose Levels in Children with Type 1 Diabetes. Pediatric Diabetes. 2018;19(4):809-815. PMID 29527759. https://pubmed.ncbi.nlm.nih.gov/29527759/
  • Murugesan R, Kumar J, Thiruselvam S, et al. Food Order Affects Blood Glucose and Insulin Levels in Women with Gestational Diabetes. Frontiers in Nutrition. 2024;11:1512231. PMID 39777075. https://pubmed.ncbi.nlm.nih.gov/39777075/